There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

Support materials for PEMFC and DMFC electrocatalysts—A review

Over the past few decades, direct methanol fuel cells (DMFCs) have been intensively developed as clean and high-efficiency energy conversion devices. However, their dependence on expensive Pt-based catalysts for both the anode and the cathode make them unsuitable for large-scale commercialisation. The essential solution to addressing this shortfall is the development of low-Pt and non-Pt catalysts. Regarding this issue, considerable advances have been made with low-Pt alloys and core-shell-like catalysts, as well as non-platinum Pd–Me, Ru–Se and heat-treated MeNxCy-based catalysts. This perspective reviews potential pathways for increasing the cost-effectiveness and efficiency of these catalysts. Fundamental understanding of the composition–activity and structure–activity relationships, innovative synthesis, and promising developmental directions are highlighted. Regarding durability, the main degradation mechanism of these catalysts and the corresponding mitigating strategies are presented.

Recent advances in catalysts for direct methanol fuel cells

Review on the criteria anticipated for the fabrication of highly efficient ZnO-based visible-light-driven photocatalysts

Core–shell Co3O4/ZnCo2O4 coconut-like hollow spheres are synthesized by a facile two-step method. As the anode of lithium-ion batteries, their reversible capacity is up to 1278 mA h g−1 at 0.1C rate and remains at 1093 mA h g−1 after 50 cycles, much higher than that of pure Co3O4. Even after 300 cycles (cycling for more than 4 months), their reversible capacity can maintain at 934 mA h g−1 at 0.2C rate. Such superior electrochemical performance (high reversible capacity, excellent long-term cycling stability and good rate capability) can be ascribed to the unique core–shell hollow structure, complex synergistic effect, good electrical conductivity and interfacial charging mechanism. The present results demonstrate that the core–shell Co3O4/ZnCo2O4 hollow spheres are promising anode materials for high-performance lithium-ion batteries.

Core–shell Co3O4/ZnCo2O4 coconut-like hollow spheres with extremely high performance as anode materials for lithium-ion batteries

α-MoO3–In2O3 core–shell nanorods were prepared by a facile two-step hydrothermal method. As the anode of lithium-ion batteries, their reversible capacity was up to 1304 mA h g−1 at 0.2 C rate (5 hours per half cycle) and maintains 1114 mA h g−1 after 50 cycles. At a rate of 0.3 C, 0.5 C, 1 C and 2 C, the discharge capacities after 50 cycles were maintained at 938, 791, 599 and 443 mA h g−1, respectively. The enhanced electrochemical performance can be ascribed to the synergistic effect between α-MoO3 and In2O3, one-dimensional core–shell nanostructures, short paths for lithium diffusion and interface spaces.

Qiang Wang

Papers

Core–shell Co3O4/ZnCo2O4 coconut-like hollow spheres with extremely high performance as anode materials for lithium-ion batteries

Electrochemical performance of α-MoO3–In2O3 core–shell nanorods as anode materials for lithium-ion batteries

High capacity and cyclability of hierarchical MoS2/SnO2 nanocomposites as the cathode of lithium-sulfur battery

Relationship of microstructure, mechanical properties and titanium cutting performance of TiAlN/TiAlSiN composite coated tool

High electrochemical performances of α-MoO3@MnO2 core-shell nanorods as lithium-ion battery anodes