Boron-substituted manganese spinel oxide cathode for lithium ion battery

An attempt has been made to synthesize boron-substituted cubic spinel through solid state (SS) and solution route (SR) techniques. The synthesized spinels have been examined for their physical and electrochemical characteristics through ex situ-X-ray diffractometry (XRD) and SEM, as well as by charge-discharge cycling and diffusion coefficient measurements. X-ray diffraction reveals boron elimination from boron-substituted spinel (SR-B spinel) resulting in phase splitting to lithium berate glass formation and parent cubic spinel when subjected to heating at and above 600 degreesC. Synthesis through SR with precursor material calcined at 500 degreesC only provides high discharge capacity with good cyclability. The measurement of diffusion coefficient of lithium supports that boron got substituted at 16d site in Fd (3) over barm spinel structure. This paper discusses the mechanism underlying the stability of boron-substituted spinel and the suitability of LiB1/9Mn17/9O4 as a promising positive electrode candidate for lithium ion battery. (C) 2001 Elsevier Science B.V. All rights reserved.