Facets regulation of Li1.6Mn1.6O4 by B-doping to enable high stability and adsorption capacity for lithium extraction

Abstract

Spinel lithium manganese oxide Li1.6Mn1.6O4 (LMO) is a promising ion sieve material with high adsorption capacity and selectivity for lithium recovery from salt lake brines. However, manganese dissolution seriously hinders its application. In this work, B-doping is used to promote the growth of (100) facets and inhibit the growth of (110) facets of Li1.6Mn1.6O4, which could effectively inhibit dissolution and enhance the stability of LMO. For 8 % B-doped Li1.6Mn1.6O4 (LBMO-0.08), the Mn dissolution decreases from 2.13 % to 1.93 %, the adsorption capacity achieves 42.6 mg·g−1. The DFT calculations provide further evidence that the structure stability of Li1.6Mn1.6O4 is enhanced by B-doping. Additionally, LBMO-0.08 exhibits fast adsorption kinetics, and the equilibrium time is 6 h, which is lower than most reported literatures. After granulation, particles containing 75 wt% LBMO-0.08 represent high adsorption capacity for lithium (16.35 mg·g−1) and considerable selectivity in Qarhan salt lake brine, which have great superiority to separate lithium from salt lake brine in practical applications.