Kenta Ooi

Abstract: A hollandite-type manganese dioxide (HolMO), without foreign metal cations (K[sup +], NH[sup +][sub 4], Na[sup +]) in the (2 [times] 2) tunnel, was prepared directly by reacting LiMnO[sub 4] with Mn(NO[sub 3])[sub 2] in an H[sub 2]SO[sub 4] acidic solution. The HolMO belonged to a body-centered tetragonal system (space group 14.m) and could be expressed by the formula H[sub 4x]Mn[sub 8[minus]x]O[sub 16][center dot]yH[sub 2]O. A preliminary electrochemical study suggested that the HolMO is promising as the cathode for a lithium rechargeable battery.

TL;DR: In this paper, the chemical diffusion coefficients of lithium ions in the manganese oxide were evaluated from cyclic voltammetry (CV) and potential step chronoamperometry (PSCA), using a finite diffusion model.

TL;DR: In this article, the insertion of alkali-metal ions in the aqueous phase was investigated by using a Pt/MnO 2 electrode which was obtained by the electrochemical extraction of Li + from a Pt /LiMn 2 O 4 electrode.

TL;DR: In this paper, the kinetics of lithium electroinsertion into a Pt/{lambda}-MnO{sub 2} thin-film electrode in a 10 mmol/dm{sup 3} LiCl solution was studied by ac impedance spectroscopy between 10{sup {minus}4} and 10{Sup 2} Hz at 25 C. The results showed that solid-state diffusion of Li{sup +} ions is a rate-determining process in the system.

TL;DR: In this article, a graphite oxide (GO)−birnessite manganese oxide (BirMO) nanocomposite was synthesized via restacking of the GO layers encapsulated with Li−BirMO layers, which precipitated in situ on the surfaces of exfoliated GO sheets.