Preparation and electrochemical performance of Li ₂ MnSiO ₄ cathode material doped with chromium on manganese site

Abstract

In this work, Li 2 Mn 1-x Cr x SiO 4 cathode material was synthesized by the solidphase doping method and two-step calcination. The appropriate calcination temperature can be obtained by TG-DTA curve. XRD, SEM and TEM tests show that the prepared Li 2 Mn 1-x Cr x SiO 4 has a Pmn2 1 space group structure, and the particle size decreases from 570 to 140 nm with the increase of the doped Cr content. Cr doping enhances the structural stability of Li 2 Mn 1-x Cr x SiO 4 and improves the electrochemical activity of the cathode. The results of XRD, EDS and XPS show that Cr 3+ is successfully doped into the Li 2 MnSiO 4 lattice, and the element distribution is uniform. The electrochemical results show that Li 2 Mn 0.8 Cr 0.2 SiO 4 exhibits significantly enhanced cycle stability and discharge capability.

Lithiated Manganese-Based Materials for Lithium-Ion Capacitor: A Review

“…Lithium orthosilicates, Li 2 MSiO 4 (M = Mn, Fe, Co), have caught the attention of several researchers as high-capacity electrode materials for Li-ion batteries and hybrid supercapacitors [61][62][63]. Due to their many enticing qualities, including their high theoretical capacity (330 mA h g −1 ) when more than one lithium ion is extracted per formula unit, they are becoming increasingly popular [72][73][74]. The extraction of more than one lithium ion per formula unit provides high thermal stability [35]; Li 2 MnSiO 4 is a more promising orthosilicate electrode material because it allows for the reversible extraction of two moles of Li + ions utilizing the Mn 2+ /Mn 3+ and Mn 3+ /Mn 4+ redox couples, and this results in a greater energy density [74,75].…”