Enhanced Rate Performance of Al-Doped Li-Rich Layered Cathode Material via Nucleation and Post-solvothermal Method

Abstract

Al-doped layered cathode materials Li1.5–x Al x Mn0.675Ni0.1675Co0.1675O2 have been successfully synthesized via a rapid nucleation and post-solvothermal method. The surface morphology and crystal structures of Al-doped Li-rich materials are investigated via scanning electron microscopy, X-ray diffraction, Raman spectra, and X-ray photoelectron spectroscopy. After optimization, the Li1.45Al0.05Mn0.675Ni0.1675Co0.1675O2 (Al = 0.05) sample showed excellent electrochemical performance, and the discharge capacities are 323.7 and 120 mAh g–1 at a rate of 0.1 and 20 C, respectively. These improvements, based on electrochemical performance evaluation and density functional theory calculations, might be ascribed to the increased electron conductivity of layered Li-rich material via Al3+ ions doped into a crystal structure.

Oxygen Release Degradation in Li‐Ion Battery Cathode Materials: Mechanisms and Mitigating Approaches

“…Substituting 10% of Co cations with Al is shown to be promising in stabilizing the structure resulting in ≈100 °C delay in the thermal decomposition of NMC cathodes . Such observation is explained by higher stability of Al ions in the intermediate tetrahedral sites that increases the energy barrier for migration of transition metals and promotes the structural stability . Similarly, addition of Fe 3+ to the spinel LMNO cathodes has shown to improve the thermal stability by alleviating the oxygen release reaction.…”

“…Doping and cationic substitution of transition metals is one of the most widely explored approaches in improving the structural stability of the cathode materials. As such, the effect of the monovalent cations such as K and Na, [155][156][157][158][159][160][161][162] divalent ion dopants such as Mg and Zn, [163][164][165][166][167][168][169][170] trivalent Fe, Al and Au dopants, [140,[171][172][173][174][175][176][177][178][179][180][181][182][183][184][185][186][187][188] and tetravalent cations such as Ti and Ru [189][190][191][192][193][194][195] have been studied on the structural stability of various cathode materials. It has been demonstrated that dopants with various valence groups can affect the structure and the properties of the cathode materials in different ways.…”

The role of metal substitutions in the development of Li batteries, part I: cathodes

“…In Li 1.5 Mn 0.675 Ni 0.1675-Co 0.1675 O 2 , Al 3+ occupies Li + sites, improving the kinetics of lithiation/delithiation and reducing impedance, thus increasing rate performance. 300 In Li[Li 0.23 Ni 0.15 Mn 0.52 Al 0.10 ]O 2 it was found that the presence of Al improved long-term cycling performance, and rate performance. 301 It has been hypothesized that Al helps prevent Mn migration causing the conversion to spinel-like phases.…”

Modifying Li@Mn6 Superstructure Units by Al Substitution to Enhance the Long‐Cycle Performance of Co‐Free Li‐Rich Cathode

“…[ 18 ] It is noticed that, Al doping has been extensively adopted to promote the electrochemical performance of Li‐rich layered cathodes in the past decade. [ 19–24 ] Dianat et al. found that Al doping could stabilize layered structure and inhibit irreversible structural variation in Li‐rich cathodes through theoretical calculations.…”