High-voltage lithium cathode materials

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].…”

On the Synthesis of Ramsdellite LiTiMO4 (M = Ti, V, Cr, Mn, Fe): An Experimental and Computational Study of the Spinel–Ramsdellite Transformation

“…[4,5,8] redox couple in related systems. [37,38] Since the average oxidative voltage of LiTi 2 O 4 has increased by more than 1 and 2 V for LiTiVO 4 and LiTiCrO 4 , respectively, the electro-chemical performance of a lithium cell made from either LiTiVO 4 (R) or LiTiCrO 4 (R) as the positive electrode is much better. The maximum quantity of lithium that can be de-intercalated is expected to be constant as it is limited by the content of lithium and M 3+ (one ion per formula unit), therefore the maximum theoretical capacity of LiTiVO 4 (R) or LiTiCrO 4 (R) is around 160 mAh g -1 , as in LiTi 2 O 4 .…”

XPS investigations of valence changes during cycling of LiCrMnO4‐based cathodes in Li‐ion batteries

“…In this field, the requirements are high energy density (W h/kg), extremely long durability (>10 years), high safety and low cost. A straightforward possibility to achieve high energy density is to increase the cell voltage (to E > 5 V [4] ) and/or by increasing the specific capacity (A h/kg). Possible candidate materials are spinel-type structures derived from LiMn 2 O 4 by replacing manganese with Ni, Co or Cr.…”

“…In the present paper, LiCrMnO 4 with a cell voltage of about 5.2 V at complete de-intercalation was investigated. One problem with this material is the drastic decrease of capacity during cycling when charging to this final voltage (see inset in Fig.…”