Sangbaek Park

Stretchable and self-healing (SH) energy storage devices are indispensable elements in energy-autonomous electronic skin. However, the current collectors are not self-healable nor intrinsically stretchable, they mostly rely on strain-accommodating structures that require complex processing, are often limited in stretchability, and suffer from low device packing density and fragility. Here, an SH conductor comprising nickel flakes, eutectic gallium indium particles (EGaInPs), and carboxylated pol

Abstract Hollow carbon materials are considered promising sulfur reservoirs for lithium–sulfur batteries owing to their internal void space and porous conductive shell, providing high loading and utilization of sulfur. Since the pores in carbon materials play a critical role in the infusion of sulfur, access of the electrolyte, and the passage of lithium polysulfides (LPSs), the creation and tuning of hierarchical pore structures is strongly required to improve the electrochemical properties of

A particle-based photocatalyst with a permanent internal field prepared by a corona poling method is presented as a novel approach to enhance the hydrogen evolution reaction in a particulate-suspension system. Photocatalytic activity of K0.5Na0.5NbO3 was significantly improved by 7.4 times after the polarization.

Abstract The recent boom in deformable or stretchable electronics, flexible transparent displays/screens, and their integration into the human body has facilitated the development of multifunctional energy devices that are stretchable, transparent, wearable, and/or biocompatible while meeting the energy or power requirements. The development of soft energy systems begins with the preparation of relevant conductors and the design of innovative device configurations. In this study, recent advances

Stretchable energy storage devices are prerequisites for the realization of autonomous elastomeric electronics. Microsupercapacitors (MSCs) are promising candidates for this purpose due to their high power and energy densities, potential for miniaturization, and feasibility of embedding in circuits; however, efforts to realize stretchable MSCs have mostly relied on strain-accommodating materials and have suffered from limited stretchability, low conductivity, or complicated patterning processes.

Transparent and stretchable Ag-Ni and Ag-Fe core-shell nanowire networks were fabricated as a cathode and anode, respectively, for asymmetric supercapacitors. Both electrodes showed a reversible stretchability at up to 100% strain and exhibited high electrochemical stability and specific capacitances of ∼3 mF cm^-2 with 50% optical transmittance. The asymmetric device assembled with a PVA/KOH electrolyte demonstrated a high operating voltage of 1.6 V and an excellent capacitance retent

We report the facile, one-pot synthesis of 3-D urchin-like W18O49 nanostructures (U-WO) via a simple solvothermal approach. An excellent supercapacitive performance was achieved by the U-WO because of its large Brunauer–Emmett–Teller (BET) specific surface area (ca. 123 m2·g–1) and unique morphological and structural features. The U-WO electrodes not only exhibit a high rate-capability with a specific capacitance (Csp) of ~235 F·g–1 at a current density of 20 A·g–1, but also superior long-life p

Anisotropic two-dimensional (2D) nanosheets of the layered perovskite, Ba5Nb4O15, with thicknesses of 5-10 nm and lateral sizes of 300-1200 nm, were synthesized by a hydrothermal route. The influences of the 2D morphology of the material on the crystal and electronic structures, light absorption properties, and photocatalytic activity were investigated. The ultrathin nanosheets showed much-enhanced photocatalytic activity compared to both thick nanosheets (∼30 nm) and micrometer-sized particles

Contact pressures in the articular cartilage during gait affect injuries and the degenerative arthritis of knee and ankle joints. However, only contact forces at the knee and ankle joints during gait can be estimated by using a rigid body dynamic model. The contact pressure distribution can be obtained quantitatively for a static posture by using finite element (FE) analysis in most cases. The purpose of this study is to develop a new method to obtain the contact pressure distribution at the kne

Recent efforts have focused on the fabrication and application of three-dimensional (3-D) nanoarchitecture electrodes, which can exhibit excellent electrochemical performance. Herein, a novel strategy towards the design and synthesis of size- and thickness-tunable two-dimensional (2-D) MnO2 nanosheets on highly conductive one-dimensional (1-D) backbone arrays has been developed via a facile, one-step enhanced chemical bath deposition (ECBD) method at a low temperature (∼50 °C). Inclusion of an o

High-quality, single-crystalline Sb-doped SnO2 (ATO) nanobelts (NBs) surrounded by very thin and short TiO2 rutile nanorods were synthesized by thermal evaporation followed by chemical bath deposition. An epitaxial relationship between ATO NBs and rutile-phase TiO2 nanorods was clearly demonstrated on the basis of a crystallographic approach through high-resolution transmission electron microscopy analysis. Furthermore, the ATO@TiO2 heteronanostructures as anodes for Li ion batteries showed enha

Although lithium-sulfur batteries exhibit a fivefold higher energy density than commercial lithium-ion batteries, their volume expansion and insulating nature, and intrinsic polysulfide shuttle have hindered their practical application. An alternative sulfur host is necessary to realize porous, conductive, and polar functions; however, there is a tradeoff among these three critical factors in material design. Here, the authors report a layered porous carbon (LPC) with VO₂ /V<sub>3</su