Carbon-coated TiO ₂ (TiO ₂ /C) nanopowders were synthesized as a negative electrode material for sodium secondary batteries. The TiO ₂ /C negative electrode delivers a high reversible discharge capacity of 275 mA h g ⁻¹ at 10 mA g ⁻¹ at 363 K.

The hydrogen impermeability of titanium nitride films and its dependence on nitrogen concentration have been estimated by molten salt electrochemical techniques at 723 K. Surface nitriding of titanium substrates was conducted by two methods, i.e., gas nitriding and molten salt electrochemical nitriding. Hydrogen concentration in the titanium nitride films was directly measured by elastic recoil detection (ERD) analysis. It was confirmed that the titanium nitride film worked as a hydrogen permeation barrier at high temperatures. When titanium coexisted with titanium nitrides, the hydrogen impermeability decreased with the increase of the volume concentration of titanium, which worked as the hydrogen-diffusing medium. © 2000 The Electrochemical Society. All rights reserved.

In this study, submicron-sized tin particles were used as the negative electrode material for potassium secondary batteries. With a bis(fluorosulfonyl)amide-based ionic liquid electrolyte, K[FSA]–[C₃C₁pyrr][FSA], the tin negative electrodes showed improved capacity retention of over 170 mA h (g-Sn)⁻¹ after 100 cycles at room temperature.

Silicon solar cells are crucial devices for generating renewable energy to promote the energy and environmental fields. Presently, high-purity silicon, which is employed in solar cells, is manufactured commercially via the Siemens process. This process is based on hydrogen reduction and/or the thermal decomposition of trichlorosilane gas. The electrochemical process of producing silicon has attracted enormous attention as an alternative to the existing Siemens process. Thus, this article reviews different scientific investigations of the electrochemical production of silicon by classifying them based on the employed principles (electrorefining, electrowinning, and solid-state reduction) and electrolytes (molten oxides, fluorides, chlorides, fluorides–chlorides, ionic liquids [ILs], and organic solvents). The features of the electrolytic production of silicon in each electrolyte, as well as the prospects, are discussed.