Chung-Ang University research – Science

Chung-Ang University Researchers Innovate Interlayer Material to Enhance Lithium-Sulfur Battery Performance

SCIENMAG — Thu, 06 Nov 2025 12:10:39 +0000

In a groundbreaking advancement poised to reshape the future of energy storage, a research team from Chung-Ang University in South Korea has unveiled an innovative material design that could significantly enhance the performance and durability of lithium–sulfur (Li–S) batteries. Led by Associate Professors Seung-Keun Park and Inho Nam, their work presents a sophisticated dual-level engineering strategy that integrates metal–organic framework (MOF)-derived hierarchical porous carbon nanofibers embedded with low-coordinated cobalt single-atom catalysts. This architectural innovation addresses the inherent challenges that have long hindered Li–S battery commercialization, propelling the technology closer to practical applications in electric vehicles, renewable energy storage, and flexible electronics.

Lithium–sulfur batteries are heralded for their exceptional theoretical energy density, surpassing that of conventional lithium-ion batteries, which have dominated the energy storage market for decades. However, the practical deployment of Li–S batteries has been impeded by several critical issues, including the polysulfide shuttle effect—where soluble lithium polysulfides dissolve into the electrolyte and migrate between electrodes—resulting in rapid capacity fading and low coulombic efficiency. Additionally, sluggish redox kinetics and material instability further degrade battery lifespan and performance. To overcome these obstacles, researchers must devise strategies that simultaneously enhance the materials’ structural and catalytic properties at both the microscopic and atomic levels.

The novel approach adopted by the Chung-Ang University team involves the synthesis of hierarchical porous carbon nanofibers derived from MOFs, which serve as a robust and conductive scaffold. This scaffold features abundant pore networks providing enhanced electrolyte accessibility and facilitating lithium-ion transport. Crucially, within these porous carbon frameworks, the researchers have incorporated cobalt single atoms coordinated in a low-coordination N_3 environment—an atomic configuration designed to optimize catalytic activity towards lithium polysulfide adsorption and conversion. This precise atomic-level modification uniquely promotes rapid redox reactions and minimizes polysulfide dissolution, thus suppressing the notorious shuttle effect.

Delving deeper into the catalytic mechanism, the low-coordinated cobalt center acts as an active site that strongly adsorbs lithium polysulfides, effectively anchoring them on the cathode side and preventing their diffusion. This strong adsorption affinity results in accelerated conversion of polysulfides to insoluble lithium sulfide phases during discharge, and conversely, their efficient reoxidation during charge. Such kinetic enhancement translates to superior battery performance, with heightened capacity retention and reliable operation at high charge–discharge rates, even after extensive cycling. This stability is critical for real-world applications where battery longevity and reliability are paramount.

From a materials science perspective, the hierarchical porous carbon nanofiber architecture contributes significantly by providing mechanical integrity and flexibility. Unlike traditional electrode materials, which often require binders and additional conductive additives, this free-standing, binder-free material can function directly as an interlayer within battery cells. Its flexible nature allows it to maintain structural cohesion under mechanical stress, such as bending or folding, which broadens its utility in emerging flexible and wearable electronic devices that demand not only high energy density but also adaptability and durability.

The synthesis of this dual-level engineered material hinges on leveraging the versatility of MOFs as precursors. MOFs possess tunable porosity and customizable chemical environments, enabling precise morphological and compositional control during thermal conversion into carbon nanostructures. This method ensures uniform dispersion of cobalt single atoms and the formation of the desired coordination environment, which are challenging to achieve through conventional synthesis techniques. This innovative synthesis route offers a path towards scalable production, an essential step toward commercial viability.

In addressing the polysulfide shuttle and slow reaction kinetics via this dual strategy, the team’s research not only surmounts key electrochemical performance barriers but also highlights the paramount importance of integrating macrostructural design with atomic-level catalyst engineering. This insight marks a paradigm shift in the way battery materials are conceptualized, encouraging more holistic, multiscale approaches that bridge the gap between fundamental chemistry and practical device engineering.

Considering future implications, this advancement lays a strong foundation for next-generation Li–S batteries with capabilities tailored for high-energy storage requirements. Electric vehicles stand to benefit from longer driving ranges and faster charging times, addressing two of the foremost consumer demands. Similarly, grid-scale energy storage systems for renewable sources such as solar and wind could exploit these batteries to store intermittent energy more efficiently and sustainably. Furthermore, the lightweight and flexible nature of the developed material opens avenues for integration into portable and wearable technologies, catalyzing innovations in how we power and interact with devices.

The societal impact of such battery improvements cannot be overstated. By fostering safer, more efficient, and cost-effective energy storage solutions, these materials directly contribute to the global transition toward a cleaner, low-carbon energy infrastructure. Reduced reliance on scarce and expensive raw materials through enhanced battery cycle life and material efficiency aligns with sustainable development goals, opening possibilities for wider accessibility to green technologies in both developed and emerging markets.

Dr. Park elaborates on their research ethos, emphasizing that “overcoming the intrinsic limitations of lithium-ion technologies requires deep integration of atomic-level catalytic design with macrostructural engineering to address complex electrochemical phenomena such as polysulfide shuttling.” Concurrently, Dr. Nam highlights the practical significance, noting that their free-standing, binder-free material resists mechanical failure even under rigorous use cases, making it immediately applicable for pouch cell configurations and flexible battery formats.

As the quest for better energy storage continues, this study underscores the vast potential locked within intelligently designed nanomaterial frameworks, where atomic precision meets scalable engineering. The promising electrochemical metrics achieved—encompassing high capacity retention and robust rate capability over hundreds of cycles—validate the dual-engineering approach as a versatile platform for future battery innovations.

This pioneering work published in “Advanced Fiber Materials” paves a new route for lithium–sulfur battery development. It encourages the research community to revisit fundamental assumptions about catalyst coordination and substrate architecture, potentially igniting a wave of material innovations that accelerate the arrival of next-generation energy solutions.

Subject of Research: Not applicable

Article Title: Dual‑Level Engineering of MOF‑Derived Hierarchical Porous Carbon Nanofibers with Low‑Coordinated Cobalt Single‑Atom Catalysts for High‑Performance Lithium–Sulfur Batteries

News Publication Date: 24-Sep-2025

References: DOI: 10.1007/s42765-025-00614-w

Image Credits: Seung-Keun Park and Inho Nam from Chung-Ang University

Keywords

Energy storage, Batteries, Materials science, Nanotechnology, Chemical engineering, Catalysis, Sustainable energy, Renewable energy

Chung-Ang University Scientists Uncover Unusual Behaviors in Nanoparticle Growth and Shrinkage

SCIENMAG — Thu, 28 Aug 2025 11:11:36 +0000

In a landmark study that promises to reshape the landscape of nanoscience, researchers at Chung-Ang University in South Korea have unveiled a groundbreaking theoretical framework to decode the complex growth behaviors of nanoparticles. Nanoparticles, whose diminutive sizes confer unique physical and chemical properties, are foundational elements in cutting-edge technologies such as quantum-dot displays, nanocatalysts, and advanced drug delivery systems. Despite their widespread utilization and intensive study, the precise mechanisms governing the uniform formation and growth of these tiny particles have long eluded scientists. Addressing this enigma, the new theory provides unprecedented insights into the multiphasic and size-dependent dynamics that dictate nanoparticle ensemble growth.

Historically, the classical nucleation theory (CNT) rooted in the Gibbs-Thomson equation has served as the cornerstone for understanding nanoparticle generation and growth over the last century. CNT rationalizes particle formation via thermodynamic considerations, describing how atoms or molecules overcome an energy barrier to nucleate new phases. However, this classical framework falls short in explaining the emergence of narrowly distributed particle sizes and the intricate temporal evolution observed in nanoparticle systems. The inability of CNT to reconcile these observations has propelled researchers to seek alternative models that incorporate more nuanced physical and chemical processes.

The study, spearheaded by Professor Jaeyoung Sung and his interdisciplinary team from the Department of Chemistry and the Global Science Research Center for Systems Chemistry at Chung-Ang University, represents a significant leap forward. By leveraging real-time, in-situ liquid-phase transmission electron microscopy (TEM), the researchers tracked the growth trajectories of hundreds of nanoparticles on the scale of just a few nanometers. These observations revealed that nanoparticle growth is characterized by multiple kinetic phases, each exhibiting distinct statistical behaviors in terms of size distribution and growth rates. Moreover, the data highlighted that nanoparticle coalescence—the process where two or more particles merge—occurs predominantly within a sharply confined time window, an aspect inadequately addressed by previous theories.

The intricate size-dependent growth patterns captured through liquid-phase TEM challenged conventional wisdom and underscored the necessity of a more comprehensive theoretical approach. In response, the team formulated a novel model that integrates six pivotal factors influencing nanoparticle growth: nanoparticle energy states, geometric shape, configurational degeneracy (the number of ways a system’s configuration can be arranged without changing its energy), monomer diffusion coefficients, and monomer association rates on the particle surface. Crucially, the theory transcends previous limitations by incorporating nanoparticle translation, rotation, and vibrational dynamics, as well as interactions with surrounding molecular species—parameters that were notably absent in classical frameworks.

This enriched model elucidates how motion and configurational entropy fundamentally influence nucleation and growth processes, offering an unprecedented quantitative fit to experimental growth trajectories. The robustness of the theory was validated across various nanoparticle systems, including platinum nanoparticles synthesized through multiple precursor chemistries, as well as metal oxide and semiconductor nanoparticles, evidencing broad applicability under diverse experimental environments. Remarkably, the theory predicts a counterintuitive phenomenon wherein smaller nanoparticles continue to grow while larger particles dissolve, directly challenging the conventional Ostwald ripening paradigm that has dominated nanoparticle science for a century. This insight accounts elegantly for the observed size focusing phenomena and the emergence of uniform particle populations.

Professor Jungwon Park of Seoul National University, an expert in liquid-phase TEM involved in the experimental component of the study, emphasized the transformative nature of these findings. The ability to observe and model nanoparticle ensembles in real time lays the groundwork for understanding size distribution dynamics beyond the reach of prior experimental or theoretical techniques. Furthermore, this work paves the way for leveraging fundamental physics to unravel the complexity of nanoparticle systems, thereby enabling predictive control over nanoscale synthesis.

On the theoretical front, Distinguished Professor Taeghwan Hyeon, Director of the IBS Center for Nanoparticle Research, hailed this research as signaling “a fundamental shift” in how the scientific community comprehends nanoparticle formation and evolution over time. Traditionally, nanoparticle growth has been simplified to thermodynamic processes devoid of intricate kinetic and dynamic considerations. By contrast, this new framework acknowledges the multiphase and dynamic nature of real-world nanoparticle growth, capturing the subtleties that govern size distribution and stability.

Beyond materials science, the implications of this theory extend into biological and medical domains. Professor Sung highlighted that the mathematical structure of their model can be adapted to comprehend the formation and aggregation dynamics of biological condensates, implicated in neurodegenerative diseases such as Alzheimer’s. The connection between physical principles delineated in nanoparticle growth and pathological protein aggregation opens promising interdisciplinary research avenues, potentially guiding therapeutic interventions.

The study’s authors also stress the synergy between their theoretical advances and emerging computational methodologies. By combining their model with state-of-the-art artificial intelligence and computational chemistry techniques, they foresee a future where nanoparticle synthesis can be predictively controlled with high precision. This predictive capability marks a milestone toward the rational design of nanoparticles tailored for specific industrial applications, including catalysis, semiconductor manufacturing, and targeted drug delivery systems. The ability to engineer nanoparticles with predetermined size distributions and functional properties holds the promise of revolutionizing multiple technology sectors.

This research was meticulously published in the June 2025 issue of the prestigious journal Proceedings of the National Academy of Sciences. It serves as a testament to the power of integrating experimental innovation with rigorous theoretical development. The combination of in situ liquid-phase TEM observations with the novel multiphasic growth model equips scientists with a powerful toolkit to dissect and manipulate nanoparticle dynamics with hitherto unmatched fidelity.

Overall, the work from Chung-Ang University not only addresses a century-old challenge in nanoscience but also charts a compelling new course for future investigations. As nanoparticle applications continuously expand—from energy conversion to medicine and electronics—the ability to precisely direct their synthesis and growth will become increasingly pivotal. By unveiling the hidden complexities of nanoparticle growth kinetics and providing a robust theoretical framework, this study catalyzes a new era of controlled nanomaterial innovation.

Subject of Research: Nanoparticle Growth Dynamics

Article Title: Multiphasic size-dependent growth dynamics of nanoparticle ensembles

News Publication Date: 4-Jun-2025

Web References:
Chung-Ang University Chemistry Department
PNAS Article DOI

References:
DOI: 10.1073/pnas.2424950122

Image Credits:
PhD student Jingyu Kang, Dr. Ji-Hyun Kim, and Professor Jaeyoung Sung from Chung-Ang University

Keywords

Nanoparticles, Semiconductors, Quantum dots, Materials science, Drug delivery, Nanomaterials, Electron microscopy, Catalysis, Colloids, Physical chemistry