Rechargeable Li-ion batteries have been widely used in consumer electronics and electric vehicles. The rapidly growing electric vehicle market is driving a burgeoning demand for Li-ion batteries with high energy density and low cost. Among the components of a Li-ion cell, cathodes are currently the primary constraint on energy density and dominate the battery cost. Achieving high capacity in cathodes necessitates a combination of high cyclable Li content, fast Li kinetics, and high stability during charge and discharge cycles.

In this regard, our group is dedicated to developing high energy density cathode materials that comprehensively meet various performance metrics for secondary batteries. We aim to understand the properties of cathode materials at the atomic level to rationally design new high-capacity cathodes. Furthermore, we seek to expand the boundaries of materials science and electrochemistry by exploring the relationship between high-valent redox behavior and structural properties. Our main research areas include, but not limited to, Li-rich cathodes, high-Ni cathodes, and disordered rocksalts (DRX).

Selected Publications:

(1) D. Eum and B. Kim et al.  “Voltage decay and redox asymmetry mitigation by reversible cation migration in lithium-rich layered oxide electrodes”, Nature Materials, Vol. 19, pp. 419-427 (2020)

(2) B. Kim  et al.  "Oxygen Dimerization driven Cation migration induces Voltage Hysteresis in Disordered Rocksalt Cathodes ”,  Journal of the American Chemical Society, Vol. 147, pp. 223-233 (2025)

The use of computational approaches in materials science enables the systematic and efficient exploration of materials, moving beyond traditional methods that relied on isolated insights or serendipity. First-principles calculations, such as density functional theory, allow for the investigation of materials at time and length scales that are difficult to observe experimentally. High-throughput computation significantly enhances the efficiency of materials development by reducing both time and labor costs. Furthermore, machine learning, which has been actively applied in chemistry and pharmacology, is now poised to revolutionize practices in materials science.

Our group aims to theoretically design high-performance functional materials through high-throughput computation. We evaluate synthesis feasibility, phase stability, and functional properties—including diffusion rate, voltage, and defect chemistry—using accelerated computational screening. We also perform large-scale calculations utilizing machine learning technologies. Another key focus is leveraging advanced computational methods to uncover the hidden properties of new materials, exploring them at scales that are experimentally inaccessible. By combining theoretical and experimental approaches, we strive to achieve a profound understanding of materials' properties.

Selected Publications:

(1) B. Kim et al.  “A theoretical framework for oxygen redox chemistry for sustainable batteries ”, Nature Sustainability, Vol. 5, pp. 708-716 (2022)

(2) B. Kim  et al.  “Atomistic investigation of doping effects on electrocatalytic properties of cobalt oxides for water oxidation”, Advanced Science, Vol. 5, 1801632 (2018)

(3) S. Yu et al. "Design of a trigonal halide superionic conductor by regulating cation order-disorder ”, Science Vol. 382, pp. 573-579 (2023)

The growing demand for lithium-ion batteries has raised concerns about the stability of lithium supply. Lithium reserves are limited and unevenly distributed, leading to significant price instability. In this context, sodium-ion batteries are emerging as a promising long-term alternative. Sodium, with reserves over 500 times greater than lithium, could substantially reduce the cost of secondary batteries per unit of energy.

Our group aims to address the technical challenges associated with sodium-ion batteries through two closely related research directions. First, we will explore design strategies for developing sodium-ion battery materials. Since Na+ ions differ in radius from Li+ ions, sodium-ion materials exhibit distinct structural properties compared to their lithium-ion counterparts. Therefore, we need to establish design strategies specifically tailored to sodium-ion materials. Second, we will focus on developing electrode materials for sodium-ion batteries that offer high energy density, excellent power characteristics, and long cycle life. Our goal is to continuously discover high-performance sodium-ion battery materials through high-throughput computation and comprehensive experimental studies.

Selected Publications:

(1) D. Eum, B. Kim et al.  “Coupling structural evolution and oxygen-redox electrochemistry in layered transition metal oxides”, Nature Materials, Vol. 21, pp. 664-671 (2022)