Suppressing the Lattice Oxygen Release by Al-Doped in Li-Rich Mn-Based Layered Materials

Abstract

Li-rich Mn-based layered materials (LRMs) are regarded as one of the most promising cathode materials due to their superior discharge specific-capacity. However, the irreversible lattice oxygen loss in LRMs at high voltages (＞4.5 V) leads to their poor structural stability and slow Li⁺ diffusion kinetic. To solve these problems, this work successfully synthesized the Al-doped LRMs (Li_1.2(Mn_0.54Ni_0.13Co_0.13)_1-xAl_xO₂ (x = 0, 0.01, 0.05, 0.1) by the hydrothermal method and subsequent high-temperature sintering. X-ray diffraction (XRD)，Scanning electron microscopy (SEM), and transmission electron microscopy (TEM) combined with the constant current charge-discharge tests effectively verified that Al doping effectively suppressed the irreversible lattice oxygen release and significantly improved the structural stability of LRMs.