Chromium doping as a new approach to improve the cycling performance at high temperature of 5V LiNi0.5Mn1.5O4-based positive electrode

Evaluating the performance of nanostructured materials as lithium-ion battery electrodes

“…A few drawbacks of LiMn1.5Ni0.5O4 electrodes, however, mar their application: The formation of an impurity phase LixNi1-xO seemingly worsens electrochemical performance over time and while accessible, the Ni 4+/3+ redox couple falls at potentials where electrolyte decomposition is prevalent. Addition of other transition metal cations into LiMn2-xNixO4 systems has been adopted and could prevent the formation of LixNi1-xO phases, together with reducing the cycling-induced lattice expansion [292,[300][301][302][303][304]. As an example, partial substitution of Fe for Mn or Ni in LiMn1.5Ni0.5O4 electrodes has led to enhanced electrochemical activity, most notably in terms of cycling stability and rate performance [292] (Fig.…”

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

“…The 4.1 V plateau was related to the oxidation of Mn 3+ to Mn 4+ and the 4.7 V plateau to the oxidation of Ni 2+ to Ni 4+ . The oxidation of chromium ion could bring about a high voltage of 4.9 V. Yang [20] suggested that a significant amount of Mn 4+ ion in the spinel framework was essential for electrochemical reaction to occur at around 5 V. His view was supported by Kawai [21] who argued that the presence of manganese was necessary to keep the high voltage capacity because manganese-free spinel oxides, such as Li 2 NiGe 3 O 8 , did not show any capacity above 4.5 V. The influence of doping metals including M = Cu [22][23][24], Co [25], Cr [26][27][28][29], Fe [30][31][32], Al [33,34], and Zn [35] 4 , then the corresponding capacity at 4 V will be less and that at 5 V will be large. [36,37].…”

“…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].…”

The Lattice Compatibility Theory: Supports from the Generalized Simha-Somcynsky Chemical Physics-Related Theory

“…It was recorded that these trends are not the same for Co 2+ and Co 3+ ions. The loss of stability which characterized the transition from Co(II) to Co(III) state and which was recorded by Amine et al [27,28], Duncan et al [29], Liu et al [30], Santhanam and Rambabu [31], and Aklalouch et al [32,33] has been satisfactorily explained in the Lattice Compatibility Theory (LCT) framework. The most probable explanation which can be provided through the Simha-Somcynsky theory lies in the expression of the Helmholtz free energy (see (3) and (7)).…”