Jaephil Cho

Energy-storage technologies, including electrical double-layer capacitors and rechargeable batteries, have attracted significant attention for applications in portable electronic devices, electric vehicles, bulk electricity storage at power stations, and "load leveling" of renewable sources, such as solar energy and wind power. Transforming lithium batteries and electric double-layer capacitors requires a step change in the science underpinning these devices, including the discovery of new mater

High energy-density lithium-ion batteries are in demand for portable electronic devices and electrical vehicles. Since the energy density of the batteries relies heavily on the cathode material used, major research efforts have been made to develop alternative cathode materials with a higher degree of lithium utilization and specific energy density. In particular, layered, Ni-rich, lithium transition-metal oxides can deliver higher capacity at lower cost than the conventional LiCoO2 . However, f

Abstract The layered nickel‐rich cathode materials are considered as promising cathode materials for lithium‐ion batteries (LIBs) due to their high reversible capacity and low cost. However, several significant challenges, such as the unstable powder properties and limited electrode density, hindered the practical application of the nickel‐rich cathode materials with the nickel content over 80%. Herein, important stability issues and in‐depth understanding of the nickel‐rich cathode materials on

It is expected that the market dominance of lithium-ion batteries will continue for at least another decade as there are currently no competing alternatives with the versatility of lithium-ion batteries for powering mobile and portable devices; and for buffering the fluctuating supply of intermittent energy sources such as wind and solar. While the pursuit of higher energy density and higher power density materials constitute the bulk of current interest, there is increasing interest in durable

Particle-larly good! Thermal annealing and etching of physical composite butyl-capped Si gels and SiO2 nanoparticles at 900 °C under an Ar atmosphere is a versatile method for the formation of 3D porous bulk Si particles (see picture). Complete etching of the SiO2 from the SiO2/carbon-coated Si (c-Si) composite results in the retention of the remaining c-Si as a highly porous but interconnected structure, which preserves the starting morphology.

Silicon is considered a most promising anode material for overcoming the theoretical capacity limit of carbonaceous anodes. The use of nanomethods has led to significant progress being made with Si anodes to address the severe volume change during (de)lithiation. However, less progress has been made in the practical application of Si anodes in commercial lithium-ion batteries (LIBs). The drastic increase in the energy demands of diverse industries has led to the co-utilization of Si and graphite

A support bandage for electrodes: A cross-linked polymeric binder (see picture, red) inhibits mechanical fracture of silicon negative electrodes during cycling. Nanosized silicon powder with a 3D interconnected network of poly(acrylic acid) and sodium carboxymethylcellulose as binder exhibits high reversible capacity of over 2000 mAh g−1 after 100 cycles at 30 °C while maintaining a high capacity and high current density.

Abstract Electrical energy storage and conversion is vital to a clean, sustainable, and secure energy future. Among all electrochemical energy storage devices, metal‐air batteries have potential to offer the highest energy density, representing the most promising systems for portable (electronics), mobile (electrical vehicles), and stationary (micro‐grids) applications. To date, however, many fundamental issues are yet to be overcome to realize this potential. For example, efficient catalysts fo

A high-performance LiCoO2 cathode was successively fabricated by a sol−gel coating of Al2O3 to the LiCoO2 particle surfaces and subsequent heat treatment at 600 °C for 3 h. Unlike bare LiCoO2, the Al2O3-coated LiCoO2 cathode exhibits no decrease in its original specific capacity of 174 mA h/g (vs lithium metal) and excellent capacity retention (97% of its initial capacity) between 4.4 and 2.75 V after 50 cycles. A similar excellent capacity retention of the coated LiCoO2 is also observed in a Li

Oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) along with hydrogen evolution reaction (HER) have been considered critical processes for electrochemical energy conversion and storage through metal‐air battery, fuel cell, and water electrolyzer technologies. Here, a new class of multifunctional electrocatalysts consisting of dominant metallic Ni or Co with small fraction of their oxides anchored onto nitrogen‐doped reduced graphene oxide (rGO) including Co‐CoO/N‐rGO and Ni‐NiO

The lithium‐ and manganese‐rich (LMR) layered structure cathodes exhibit one of the highest specific energies (≈900 W h kg −1 ) among all the cathode materials. However, the practical applications of LMR cathodes are still hindered by several significant challenges, including voltage fade, large initial capacity loss, poor rate capability and limited cycle life. Herein, we review the recent progress and in depth understandings on the application of LMR cathode materials from a practical point of

Abstract Reversible nanostructured electrode materials are at the center of research relating to rechargeable lithium batteries, which require high power, high capacity, and high safety. The higher capacities and higher rate capabilities for the nanostructured electrode materials than for the bulk counterparts can be attributed to the higher surface area, which reduces the overpotential and allows faster reaction kinetics at the electrode surface. These electrochemical enhancements can lead to v