The optimum conditions for synthesising LiNiO2 by a Sol-gel method and its electrochemical properties are investigated. Single-phase LiNiO2 powder is synthesised by the sol-gel method using citric acid as chelating agent and LiNO3, Ni(NO3)(2).6H(2)O as starting materials. The optimum conditions for the synthesis of LiNiO2 are calcination at 800 degreesC for 13 h in an oxygen stream after preheating at 600 degreesC for 5 h in air. The particles of LiNiO2 powder are generally in the form of a smoothly edged polyhedron and their average size is approximately 3-5 mum. The resulting LiNiO2 electrode shows relatively large discharge capacities and good cycle performance. The initial discharge capacity and that at the 20th cycle are 168 and 155 mAh g(-1) at a current density of 7.5 mA g(-1) in a voltage range 3.0-4.2 V. The decrease in the quantity of the intercalated Li ions during the first discharge as compared with that of the de-intercalated Li ions is considered to result from the destruction of the unstable tetrahedral sites and the diminution of Li atoms contained in excess.