정성균 교수

LiNi x Co y Mn z O 2 (NCM, 0 ≤ x , y , z < 1) has become one of the most important cathode materials for next‐generation lithium (Li) ion batteries due to its high capacity and cost effectiveness compared with LiCoO 2 . However, the high‐voltage operation of NCM (>4.3 V) required for high capacity is inevitably accompanied by a more rapid capacity fade over numerous cycles. Here, the degradation mechanisms of LiNi 0.5 Co 0.2 Mn 0.3 O 2 are investigated during cycling under various cutoff v

The electrochemical properties and performances of lithium-ion batteries are primarily governed by their constituent electrode materials, whose intrinsic thermodynamic and kinetic properties are understood as the determining factor. As a part of complementing the intrinsic material properties, the strategy of nanosizing has been widely applied to electrodes to improve battery performance. It has been revealed that this not only improves the kinetics of the electrode materials but is also capable

Driven by a paradigm shift from conventional liquid-based systems to all-solid-state batteries (ASSBs), the chemo-mechanical behavior of the solid–solid interface is of growing importance for understanding the intricate interfacial phenomena of ASSBs.

The key challenges in all-solid-state batteries (ASSBs) are establishing and maintaining perfect physical contact between rigid components for facile interfacial charge transfer, particularly between the solid electrolyte and cathode, during repeated electrochemical cycling. Here, we introduce inorganic-based pliable solid electrolytes that exhibit extraordinary clay-like mechanical properties (storage and loss moduli <1 MPa) at room temperature, high lithium-ion conductivity (3.6 mS cm(-

Abstract Garnet-type Li 7 La 3 Zr 2 O 12 (LLZO) solid electrolytes (SE) demonstrates appealing ionic conductivity properties for all-solid-state lithium metal battery applications. However, LLZO (electro)chemical stability in contact with the lithium metal electrode is not satisfactory for developing practical batteries. To circumvent this issue, we report the preparation of various doped cubic-phase LLZO SEs without vacancy formation (i.e., Li = 7.0 such as Li 7 La 3 Zr 0.5 Hf 0.5 Sc 0.5 Nb 0.5

All-solid-state batteries (ASSBs) are expected to address the thermal instability of conventional rechargeable batteries, given nonflammable inorganic solid electrolytes (SEs). However, the interaction between sulfide SEs and electrode materials can cause an exothermic reaction accompanied by the formation of explosive decomposition products. Herein, we demonstrate the enhanced thermal stability of a charged cathode material (Li 1– x Ni 0.6 Co 0.2 Mn 0.2 O 2, x ≈ 0.5) with a Li 3 InCl 6 halide S

Abstract The need for batteries with high energy density and safety has motivated the development of Ni‐rich layered cathodes with high thermal stability, requiring a revisit of the role of the transition‐metal ion in the phase transition accompanying the oxygen evolution of highly charged cathodes. Here, the role of the transition‐metal ion in Li x Ni 0.5 Co 0.2 Mn 0.3 O 2 ( x = 0.5, 0.33) is revealed in the phase transition and O 2 evolution occurring at high temperatures using combined in sit

2LiX-GaF 3 (X = Cl, Br, I) electrolytes offer favorable features for solid-state batteries: mechanical pliability and high conductivities. However, understanding the origin of fast ion transport in 2LiX-GaF 3 has been challenging. The ionic conductivity order of 2LiCl-GaF 3 (3.20 mS/cm) > 2LiBr-GaF 3 (0.84 mS/cm) > 2LiI-GaF 3 (0.03 mS/cm) contradicts binary LiCl (10 −12 S/cm) < LiBr (10 −10 S/cm) < LiI (10 −7 S/cm). Using multinuclear 7 Li, 71 Ga, 19 F solid-state nuclear magnetic re

Abstract Keeping both the chemical and physical state of the electrode–electrolyte interface intact is one of the greatest challenges in achieving solid‐state batteries (SSBs) with longer cycle lives. Herein, the use of organic electrolyte additives in the cathode electrolyte interphase (CEI) layer to mitigate the intertwined chemical and mechanical degradation in sulfide‐based SSBs is demonstrated. Lithium difluorobis(oxalato)phosphate (LiDFBOP) and argyrodite (Li 6 PS 5 Cl) are used as a model

The discovery of high-performance cathode materials is imperative for advances in current lithium-ion battery technology. Although extensive efforts have been focused on developing novel cathode materials, it has been a grand challenge to find candidates that can outperform state-of-the-art cathode materials such as layered, olivine, and spinel lithium transition-metal oxides. This issue arises because there are only a limited number of intercalation hosts with appropriate redox potential and li

Abstract Grid‐scale energy storage system is the need of batteries with low‐cost, high‐energy‐density, and long cycle life. The requirement promotes the discovery of cathode materials enabling the storage of charge carrier ion within the open framework crystal structure having multi‐dimensional diffusion path exhibiting small volume change. Herein, Na 2 TiFeF 7 is reported as a promising fluoride‐based cathode material for sodium‐ion batteries (SIBs). Through combined studies using various exper