Preparation of spherical LiNi_0.5Mn_1.5O₄with core-multilayer shells structure by co-precipitation method and long cycle performance

Abstract

As a promising cathode material for lithium ion battemensionalry of high voltage, spinel LiNi0.5Mn1.5O4 has attracted interest due to its high discharging voltage at 4.7 V and high energy density of 610 Wh kg-1. In this work, LiNi0.5Mn1.5O4 with a new core-multilayer shells structure (LNMO-900) is synthesized successfully by co-precipitation method and shows a better electrochemical performance. The formation of the core-multilayer shells structure is related to the kirkendall effect, the shell maintains structural stability, and improves long cycle performance. Core-multilayer shells structure is also beneficial for transmission of lithium ion, increasing rate performance. The effects of sintering temperature on the performance of LNMO were further investigated. Core-multilayer shells LiNi0.5Mn1.5O4 is synthesized successfully at 900 °C for 12 h uniquely. From the integral calculation of XPS spectra, a higher content of Mn4+ is observed in the outer shell of LNMO-900 compared with other homogeneous solid particles. The discharge specific capacity of LNMO-900 is 129.3 mAh g-1 at 1 C which is superior to others, and after 1000 cycles, LNMO-900 shows capacity retention of 87.9%. The initial capacity of LNMO-900 is 104.9 mAh g-1 at 5 C.

One-step synthesized Nb2O5−y-decorated spinel-type (Ni,V,Mn)3O4−x nanoflowers for boosting electrocatalytic reduction of nitrogen into ammonia

“…Spinel-type solid materials have received considerable attention owing to their various applications in catalysis, 29,30 energy storage, 31,32 and others. Spinel compounds have attracted great interest as catalysts because of their remarkable catalytic properties, high electrical conductivity, and robust structural stability.…”