Structural and Electrochemical Study of New LiNi_0.5Ti_xMn_1.5-xO₄ Spinel Oxides for 5-V Cathode Materials

Abstract

New LiNi0.5Ti x Mn1.5 - x O4 (0.05 ≤ x ≤ 0.6) spinel oxide materials have been obtained. The cubic unit cell parameter increases with the substitution of manganese by titanium in the octahedrally coordinated 16d sites, as evidenced by X-ray and neutron diffraction studies. For Ti-free LiNi0.5Mn1.5O4 up to x = 0.10, a decrease in the line broadening of the X-ray diffraction profiles is observed. For x > 0.1, X-ray line broadening and a progressive loss of resolution in the FTIR spectral profiles are observed. The presence of small amounts of Ti (x = 0.05 and 0.1) yields a net improvement of the electrochemical performance, whereas a deterioration of the reversible capacity is observed for large Ti contents. The electrochemical oxidation mechanism involves the appearance of two or three cubic phases with different lattice parameters, as evidenced by ex situ XRD of electrodes prepared at different depths of the first charge.

LiNi0.5Mn1.5O4 Spinel and Its Derivatives as Cathodes for Li-Ion Batteries

“…So far, many researches related to doping elements have been reported. These researches include doping Al [109], Fe [110][111][112], Cu [113], Co [114,115], Ti [116][117][118], Cr [119][120][121][122][123], Mg [124], Zn [125] and Ru [126].…”

Synthesis and electrochemical performance of Sn-doped LiNi0.5Mn1.5O4 cathode material for high-voltage lithium-ion batteries

“…Hence, LiNi0.5Mn1.5O4 still has non-negligible capacity fading during cycling due to the structural and chemical instabilities resulting from the presence of Mn 3+ ions. To solve this problem, researchers have put forth many solutions such as surface-coating [5][6][7], nanostructuring [2], and cationic-doping with ions such as Mo 6+ [8], Cr 3+ [9], B 3+ [10], Ti 4+ [11], Al 3+ [12], and W 4+ [13]. All these doped metal cations can induce differences in the cycle properties and electrical conductivity of LiNi0.5Mn1.5O4 to different extents.…”

Rate capability of spinel LiCr0.1Ni0.4Mn1.5O4

“…It will be promising if proper cation doping can be used in spinel LiNi 0.5 Mn 1.5 O 4 to further improve its electrical conductivity, favoring fast charge and discharge rate. So far, some researches related to elements have been reported, such as doping Al [1], Fe [2], Cu [3], Co [4,5], Ti [6][7][8], Cr [9][10][11][12][13], Mg [14,15] and Ru [16]. These doping elements had different influences on improving the electrochemical properties of LiNi 0.…”