Preparation and characterization of LiMn2O4 ion-sieve with high Li+ adsorption rate by ultrasonic spray pyrolysis
Abstract This study presents the preparation of LiMn 2 O 4 spinel type ion-sieves, characterization of their Li + extraction/insertion rates and discussion about the effect of the particle structure and morphology on lithium adsorption rate. LiMn 2 O 4 spinel powders were synthesized by ultrasonic spray pyrolysis and solid state reaction. LiMn 2 O 4 powder prepared by pyrolysis has agglomerate structure and spherical shape with a very uniform morphology while the other has a needle like structure with sharp edges and rough surface. Besides this, the mean particle/agglomerate size and specific surface area of the powders were relatively the same. The Li + uptake capacity of the sieve (delithiated lithium manganese powder) which has agglomerate structure was 34.9 mg/g for which the maximum adsorption capacity of the sieve was 38.67 mg/g theoretically. Besides, the sieve uptake was about 94 wt% of the maximum amount within 3 h while the other sieve required 24 h for the relatively equal uptake amount (32.8 mg/g).