Kyu Young Park

Abstract LiNiO 2 (LNO) is a promising cathode material for next‐generation Li‐ion batteries due to its exceptionally high capacity and cobalt‐free composition that enables more sustainable and ethical large‐scale manufacturing. However, its poor cycle life at high operating voltages over 4.1 V impedes its practical use, thus motivating efforts to elucidate and mitigate LiNiO 2 degradation mechanisms at high states of charge. Here, a multiscale exploration of high‐voltage degradation cascades ass

Defects critically affect the properties of materials. Thus, controlling the defect concentration often plays a pivotal role in determining performance. In lithium rechargeable batteries, the operating mechanism is based on ion transport, so large numbers of defects in the electrode crystal can significantly impede Li ion diffusion, leading to decreased electrochemical properties. Here, we introduce a new way to heal defects in crystals by a room-temperature electrochemical annealing process. We

This article introduces a new type of ‘lithium-excess Li_1+xFe_1−xPO₄’ cathode material for lithium rechargeable batteries.

Abstract Recently, the cost of lithium-ion batteries has risen as the price of lithium raw materials has soared and fluctuated. Notably, the highest cost of lithium production comes from the impurity elimination process to satisfy the battery-grade purity of over 99.5%. Consequently, re-evaluating the impact of purity becomes imperative for affordable lithium-ion batteries. In this study, we unveil that a 1% Mg impurity in the lithium precursor proves beneficial for both the lithium production p

Abstract To achieve the high energy densities demanded by emerging technologies, lithium battery electrodes need to approach the volumetric and specific capacity limits of their electrochemically active constituents, which requires minimization of the inactive components of the electrode. However, a reduction in the percentage of inactive conductive additives limits charge transport within the battery electrode, which results in compromised electrochemical performance. Here, an electrode design

Abstract Carbon‐supported Pt nanoparticles are the leading catalysts for the cathode oxygen reduction reaction (ORR) in polymer electrolyte membrane fuel cells. However, these ORR catalysts suffer from poor electrochemical durability, particularly the loss of electrochemical surface area (ECSA) due to Pt nanoparticle dissolution and agglomeration. Here, Pt loss is mitigated through a Pickering emulsion‐processing strategy that employs graphene nanoplatelet dispersions stabilized by the polymer e

The structural evolution of multi-component olivines upon delithiation and lithiation was investigated by ex-situ X-ray diffraction. We found that one-phase de/lithiation occurs for multi-component olivines for a fairly large compositional range of transition metal species given that two-phase de/lithiation is generally accepted for olivine cathodes. We discuss the driving force that determines the phase behavior (two-phase reaction vs. one-phase reaction) of olivines in terms of enthalpy of mix

Lattice volume changes in Li-ion batteries active materials are unavoidable during electrochemical cycling, posing significant engineering challenges from the particle to the electrode level. In this study, we present an elastic framework coating designed to absorb and reversibly release strain energy associated with particle volume changes, thereby enhancing mechanical resilience at both the particle and electrode levels. This framework, composed of multiwalled carbon nanotubes (MWCNTs), is app

. This study provides insights into the fast charging applications of high-Ni cathodes, thereby advancing the understanding of their behaviour and optimization.

In this paper, the structural evolution of Li(Mn_1/3Fe_1/3Co_1/3)PO₄, which is a promising multi-component olivine cathode materials, is investigated using combined <italic>in situ</italic> high-temperature X-ray diffraction and flux neutron diffraction analyses at various states of charge.

Here, we demonstrated for the first time the transient voltage variation occurring dependent on the history of current density induced.

High-Ni layered oxide cathodes are promising candidates for lithium-ion batteries due to their high energy density. However, their cycle stability is compromised by the poor mechanical durability of the particle microstructure. In this study, we investigate the impact of the calcination temperature on microstructural changes, including primary particle growth and pore evolution, using LiNi 0.88 Mn 0.08 Co 0.04 O 2 (N884), with an emphasis on the critical calcination temperature for polycrystalli