Simple and Ingenious Manner To Build Li-Rich Layered Materials with Surface Layered/Spinel Heterostructures and Li Deficiencies

Abstract

The voltage and capacity attenuation is one of the main bottlenecks limiting the commercialization of Li-rich layered materials, the introduction of a spinel structure and Li deficiencies into materials may mitigate or suppress these shortcoming. The Lirich layered materials with surface layered/spinel heterostructures and Li deficiencies (LR-S) are prepared by a simple and ingenious manner; that is, the 10 wt % precursors are added to uptake the volatilize of Li ions, which produced from the Li-rich material (LR-0) in a high-temperature post-treatment process. The generation of the spinel structure and Li deficiencies in the LR-S sample are confirmed by the inductively coupled plasma mass spectrometry, X-ray diffraction, Raman spectra, and high-resolution transmission electron microscopy characterizations. The LR-S sample displayed excellent electrochemical performances; that is, the capacity retentions is 88.92% at 1 C after 200 cycles, and the voltage drop for each cycle is 1.91 mV, respectively. The reason is mainly attributed to the spinel structure serving as a pillar structure and the Li deficiencies modulating the oxidation products of the oxygen ion in the removal/uptake process.