Preparation of electrochemically active alpha-LiFeO2 at low temperature

Electrochemically active alpha-LiFeO2 has been synthesized at low temperatu res of less than 250 degrees C via H+/Li+ ionic exchange reaction in an alc oholic solution using iron oxyhydroxide (alpha-FeOOH) and a large excess li thium hydroxide as starting materials. It was found that the presence of wa ter in the reaction bath plays a decisive role in generating the low temper ature (LT) alpha-LiFeO2 phase. The LT alpha-LiFeO2 phase, as a cathode acti ve material, was found to exhibit electrochemical rechargeability in a lith ium cell with a cycling capacity of about 0.2Li/LiFeO2 in the 1.5 V to 4.5 V range, in contrast to the non-rechargeable high temperature analog (HT al pha-LiFeO2). A preliminary X-ray diffraction study on structural changes in the cathode during cycling showed minimal lattice parameter change. (C) 19 98 Elsevier Science BN. All rights reserved.