锰基锂离子筛前体及其掺杂和表面修饰进展

Doping and Surface Modification of Lithium Manganese Oxides Used as Ion-sieve Precursor:A Review

锰基锂离子筛是一种极具发展前景的提锂吸附材料。对其晶体结构及影响其结构稳定性的因素进行了总结,重点讨论了阴离子、阳离子以及复合3种掺杂修饰和以包覆为主的表面修饰的研究概况;指出两类修饰可在一定程度上提高锰基锂离子筛的结构稳定性、抑制Jahn-Teller效应,进而降低Mn的溶损、提高循环应用的稳定性,但修饰未能从根本上解决离子筛提锂过程中溶损的关键问题,而且修饰元素的引入也为后续的分离带来新问题。最后,从以原子量低于锰的元素为掺杂对象和应用过程涉及的洗脱剂筛选两方面,对锰基锂离子筛的发展前景进行了展望。

Among varieties of adsorbents for extracting lithium from solution such as seawater, salt lake brine and geothermal water, spinel manganese oxides usually called lithium ion-sieve are the most promising ones. The crys- tal structure of spinel manganese oxides, and two factors （disproportionation reaction of Mn3＋ and Jahn-Teller effect） correlating with the structure stability are summarized respectively. Doping （anion doping, cation doping and recombi- nation doping） and surface modification （cladding, embedding and blending） are emphatically discussed in the way of enhancing the structure stability, inhibiting the Jahn-Teller effect and reducing the loss of Mn forming the skeleton of the ion-sieve. However, the loss of Mn is still known as an inhibiting factor which has not been solved through doping and surface modification at present. At the same time, the elements introduced in the doping and surface modification will bring some new trouble in the subsequent separation process. Finally, doping with less atomic weight element than Mn and application of green eluent for reducing the loss of Mn are proposed as the potential developing direction in future, and promising avenues of extraction lithium with manganese-based lithium ion-sieve are expected to meet the ever-increasing need of lithium.