Improved electrochemical performance of LiMn2O4 surface-modified by a Mn4+-rich phase for rechargeable lithium-ion batteries

Abstract

The surface of spinel LiMn2O4 is modified with different quantities of a Mn 4+ -rich phase prepared by a facile sol-gel method to improve electrochemical properties at elevated temperatures. Impurityfree and uniform morphologies for the LiMn2O4 particles are demonstrated from the X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The Mn 4+ -rich phase modified on the surface of the LiMn2O4 alleviates the dissolution of manganese in the electrolyte, thus improving the cycling performance and rate capability relative to the bare LiMn2O4. 1 wt.%modified LiMn2O4 delivers a capacity retention of 92.7% and a discharge capacity of 113.5 mAhg -1 after 200 cycles at 1 C and 25 °C, compared with that of 83.1%, and 100.8 mAhg -1 for the bare LiMn2O4. In addition, after 100 cycles, a capacity retention of 88.6% at 1 C is achieved for 1 wt.%modified LiMn2O4 at 55 °C, which is higher than the 76.0% for the bare LiMn2O4. Furthermore, this sample shows the best rate capability among all samples. The Mn 4+ -rich phase is an appropriate candidate for modifying surfaces to suppress dissolution of manganese, thereby improving the electrochemical properties of LiMn2O4.

Enhanced Cycling Stability through Erbium Doping of LiMn2O4 Cathode Material Synthesized by Sol-Gel Technique

“…Among these materials, LiMn 2 O 4 shows many virtues such as mature production technology, cheap production costs, non-pollution characteristics, and so forth [17,18,19,20]. However, the large-scale commercial applications of this material have been seriously restricted because of its poor cycling life and high-temperature performance, which are mostly a consequence of Jahn–Teller distortion, manganese dissolution, and non-uniform particle-size distribution [7,21,22,23,24]. Therefore, there is a tremendous need to optimize this material for better performance.…”

Nitrogen‐Doped Hierarchical Porous Carbon Architecture Incorporated with Cobalt Nanoparticles and Carbon Nanotubes as Efficient Electrocatalyst for Oxygen Reduction Reaction

“…The auto‐combustion (step 1) of nitrate–glycine gels is the well‐known SCS process, which is an exothermic and self‐sustaining redox reaction process by heating a mixture of metal nitrates and glycine or other organic fuels. The SCS process has been used to synthesize a variety of useful oxide materials, which shows many advantages such as fast preparation with auto‐combustion at low temperature, easy doping of elements with trace amount, and products with nanosized and/or highly porous structure . Here, in this study, we employed the glycine–nitrate‐based SCS process to produce MgO/N–C and MgO–CoO x /N–C precursors under Ar atmosphere.…”

Enhanced cycling performance of surface-doped LiMn2O4 modified by a Li2CuO2-Li2NiO2 solid solution for rechargeable lithium-ion batteries

“…Interestingly, electron diffraction patterns in the selected area of the modified layer for the 2.0 wt.% sample, were similar but not identical to those of the spinel structure, since the obtained lattice distance of 0.46 nm is slightly lower than the lattice fringe distance of 0.48 nm for the (111) plane of the spinel structure, corresponding to the shift of (111) XRD diffraction peak to higher angles. The above finding is thought to be due to the produced [43]. In order to identify the presence of Cu and Ni in the modified layer, the cross section of the 0.5 wt.% sample was characterized by energy dispersive X-ray spectrometry (EDS).…”