Structural properties of LiNi1−yCoyO2 (0≤y≤1) synthesized by wet chemistry via malic acid-assisted technique

Abstract

Abstract.We have synthesized LiNil.yCoyO 2 powders by a sol-gel method using malic acid as a chelating agent. The dependence of physico-chemical properties of the powders (crystallinity, lattice constants, grain size) has been investigated by changing the malic acid quantity and the calcination temperature for the different LiNil.yCOyO 2 oxides in the composition range 0 < y < 1. Structural studies show that a layered single phase was obtained for the y values 0.2 < y < 1.0. The local cationic environment has been studied by Raman and FTIR spectroscopy. Using acidassisted LiNil_yCOyO 2 powders (with compositions y = 0.8 and y = 0.6) calcined at 800 ~ Li//LiNivyCOyO 2 cells were assembled and tested by galvanostatic titration. These cells had an initial capacity of 140 mAh/g in the voltage range 2.8-4.2 V and showed attractive chargedischarge profiles upon cycling.

4-Volt cathode materials for rechargeable lithium batteries wet-chemistry synthesis, structure and electrochemistry

“…The shape of the charge-discharge curves shows a good reversibility even during the first cycle. In the composition domain 1.0 > x > 0.4, the shape of voltage charge profiles of the Li//LixCoO2 cell is almost similar to that recorded on high-temperature grown materials [50].…”

Lithiated cobaltates for lithium-ion batteriesStructure, morphology and electrochemistry of oxides grown by solid-state reaction, wet chemistry and film deposition

“…The homogenous mixture of the powders were packed in a shallow ceramic boat and heat treated at 450°C (melting point of LiOH) for 8 h under a flow of oxygen. Lithium cobaltate powders were also synthesized by wet chemistry method according to the sol-gel procedure reported elsewhere [6] and [7]. Pulsed laser deposited (PLD) LiCoO 2 films were grown onto silicon wafers from targets which were a mixture of LiCoO 2 powder and variable amounts of Li 2 O additive (0≤z≤15%).…”

Influence of the synthesis method on the structural and electrochemical properties of LiCo1−yNiyO2 oxides

“…Recent studies on LiCOl_yNiyO 2 cathode materials have shown that their electrochemical properties are sensitive to the structure, composition and morphology of the powders [9][10][11][12]. Particles obtained in the nanometer scale with homogeneous distribution of grain size favor the lithium-ion diffusion and improve the intercalation-deintercalation.…”