Low-spinMn3+ion in rhombohedralLiMnO2predicted by first-principles calculations

Observation of spin glass behavior in monoclinic Li0.33MnO2

“…The crystal structure of Li 0.33 MnO 2 provides two different sites for Mn ions: Mn (1) and Mn (2) [6]. The edge sharing Mn (1) O 6 and Mn (2) O 6 octahedra form a spin single and zig-zag double chains along b axis, respectively.…”

“…On the other hand, lithium manganite also show rich physical phenomena due to its unique structural, orbital and charge characteristics. For example, an abnormal low spin state of Mn 3+ ions with four 3d electrons in three t 2g orbits was proposed to be the ground state of rhombohedral LiMnO 2 by the first principle calculations and magnetic study [1,2], which has also been confirmed by the recent X-ray absorption spectra analysis [5]. Although physical characterization cannot provide a direct way on how to improve the electrochemical performance, the basic understanding of the physical properties of the cathode material is also very important since the charge capacity and capacity retention of a cathode are closely related to the cation ordering and phase stability of the material.…”

“…Lithium manganite such as rhombohedral LiMnO 2 [1,2], LiNi 0.5-Mn 0.5 O 2 [3], and spinel LiMn 2 O 4 [4] have attracted wide attention as cathode materials for Li-ion batteries because of their stable electrochemical performance, lower cost, and nontoxicity. On the other hand, lithium manganite also show rich physical phenomena due to its unique structural, orbital and charge characteristics.…”

Layered and Spinel Structural Cathodes

“…It exhibits a small monoclinic (C2/m) deformation from the ideal rhombohedral structure due to Jahn-Teller distortion of Mn 3+ . It is thermodynamically unstable, and unable to synthesized directly because of the low-spin state of Mn 3+ in LiMnO 2 [45]. Both orthorhombic and rhombohedral LiMnO 2 will transform into a spinel structure during cycling and its poor crystallinity of this phase leads to poor electrochemical properties and a spinel-like drop in the voltage profile.…”

Spin-glass-like behavior in rhombohedral Li[Li(1/3−x/3)Mn(2/3−2x/3)Nix]O2 (x=0.4)

“…As shown in the inset ofFig. 2, the high-temperature region of reciprocal ZFC curve can be well fitted by Curie-Weiss law x = C/T − Â, where x is the susceptibility, C is Curie constant and  is Weiss constant[12]. The Weiss constant are calculated to be −70(4) K which indicates strong antiferromagnetic interaction.…”