김재형 교수

A series of Ni-rich Li[Ni_<i>x</i>Co_{(1-<i>x</i>)/2}Mn_{(1-<i>x</i>)/2}]O₂ (<i>x</i> = 0.9, 0.92, 0.94, 0.96, 0.98, and 1.0) (NCM) cathodes are prepared to study their capacity fading behaviors. The intrinsic trade-off between the capacity gain and compromised cycling stability is observed for layered cathodes with <i>x</i> ≥ 0.9. The initial specific capacities of LiNiO₂ and Li[Ni_0.9Co_0.05Mn_0.05]O₂ are

Iron and nitrogen codoped carbons (Fe-N/C) have emerged as promising nonprecious metal catalysts for the oxygen reduction reaction (ORR). While Fe-N_x sites have been widely considered as active species for Fe-N/C catalysts, very recently, iron and/or iron carbide encased with carbon shells (Fe-Fe₃C@C) has been suggested as a new active site for the ORR. However, most of synthetic routes to Fe-N/C catalysts involve high-temperature pyrolysis, which unavoidably yield both Fe-

Lithium-ion batteries with high energy density, long cycle life, and appropriate safety levels are necessary to facilitate the penetration of electrified transportation systems into the automobile market.

Atomically dispersed precious metal catalysts have emerged as a frontier in catalysis. However, a robust, generic synthetic strategy toward atomically dispersed catalysts is still lacking, which has limited systematic studies revealing their general catalytic trends distinct from those of conventional nanoparticle (NP)-based catalysts. Herein, we report a general synthetic strategy toward atomically dispersed precious metal catalysts, which consists of "trapping" precious metal precursors on a h

A remarkable reduction in electronic conductivity in the core region rather than on the surface of secondary particles is proposed as a capacity-fading mechanism of a Ni-rich cathode. This result is confirmed by analyzing the electronic conductivity of the secondary particles of Li[Ni0.98Co0.01Mn0.01]O2 using the scanning spreading resistance microscopy (SSRM) mode of atomic force microscopy. SSRM analysis reveals that a much thicker rocksalt phase, which is transformed from the original layered

The kinetics for the initial stage of the hydrodesulfurization (HDS) of 4,6-dimethyldibenzothiophene (4,6-DMDBT) and dibenzothiophene (DBT) were comparatively examined over NiMo and CoMo sulfide catalysts and newly developed nickel phosphide catalysts. The HDS can proceed through an indirect hydrogenation (HYD) pathway and a direct desulfurization (DDS, or hydrogenolysis) pathway. The rate constants for the HYD and DDS pathways (k1 and k2, respectively) were estimated using a method that involve

We demonstrate Ni–N/C is an effective electrocatalyst for the direct conversion of captured CO 2 in monoethanol amine-based aqueous absorbents showing high CO faradaic efficiency (78%) and its high selectivity is maintained in various amine solvents.

Ordered mesoporous carbons (OMCs) have attracted considerable interest owing to their broad utility. OMCs reported to date comprise amorphous rod-like or tubular or graphitic rod-like frameworks, which exhibit tradeoffs between conductivity and surface area. Here we report ordered mesoporous carbons constructed with graphitic tubular frameworks (OMGCs) with tunable pore sizes and mesostructures via dual templating, using mesoporous silica and molybdenum carbide as exo- and endo-templates, respec