Progress of Research on the Manganese Oxide Ion-sieve for Extracting Lithium

Metallic lithium plays an important role in the national economy and national defense construction.With the growing demand and exhausted lithium mineral resources,it is of great significance to extract lithium from abundant liquid lithium resources such as seawater and brines.Active exploration of lithium extraction methods and technologies have been carried out.Spinel-type manganese oxide has attracted much attention because of its remarkably high selectivity for lithium ions in the aqueous phase,and it is called ion-sieve adsorbent.Being environmentally friendly and efficient,the ion-sieve adsorption method is regarded as the most promising one for extracting lithium from seawater and brines.In this review,the structure of LiMn2O4 is presented,and the development of lithium-ion insertion/extraction mechanisms is introduced as well.The synthesis method and modification of the ion-sieve precursor are also summarized in details.Moreover,the granule/membrane formation and application of lithium ion-sieves are discussed.Finally,the existing problems and the prospects of the lithium ion-sieve are put forward.