Li_1.20Mn_0.54Co_0.13Ni_0.13O₂ with Different Particle Sizes as Attractive Positive Electrode Materials for Lithium-Ion Batteries: Insights into Their Structure

Abstract

The effect of the synthesis temperature on the chemical composition of "Li 1.20 Mn 0.54 Co 0.13 Ni 0.13 O 2 " was considered using thermogravimetric analyses (TGA) and in situ X-ray diffraction (XRD) during thermal treatment. A continuous and small weight loss is observed above 800 °C because of Li evaporation, and the lamellar phase disappears to the benefit of a spinel-type phase formed above 940 °C. The layered structure is recovered upon cooling under air. "Li 1.20 Mn 0.54 Co 0.13 Ni 0.13 O 2 " materials synthesized at 800, 900, and 1000 °C show very similar compositions, structures, and electrochemical properties despite very different crystallization states. Their average structure is α-NaFeO 2 -type and described in the R3̅ m space group, with less than 0.02 Ni 2+ ions in the Li site. This peculiar composition "Li 1.20 Mn 0.54 Co 0.13 Ni 0.13 O 2 ", with one-third of large cations (Li + , Ni 2+ ) and two-thirds of small cations (Mn 4+ , Co 3+ ) promotes the extension of the cation ordering in the slabs as revealed by the √3a hex. × √3a hex. superstructure, but without full correlation between the ordered slabs along the c hex. stacking axis. Neutron and electron diffraction associated with NMR and Raman spectroscopies are shown to be efficient tools to get more insights into the average and local structures of these complex layered materials.

Synthesis and Electrode Performance of Li₄MoO₅-LiFeO₂ Binary System as Positive Electrode Materials for Rechargeable Lithium Batteries

“…3. When the cut-off voltage is low, e.g., 3.95 V, a reversible redox couple centered at 3.9 V with relatively 6 . 16 A small plateau at 2.5 V on discharge is also noted.…”

“…4,5 Recent studies reveal that charge compensation as positive electrode materials is partly achieved by negatively charged oxide ions, instead of classical transition metal ions. 6,7 Our group has recently reported that Li 3 NbO 4 with pentavalent niobium ions and Li 4 MoO 5 with hexavalent molybdenum ions are also used as new host structures for high capacity electrode materials. [8][9][10] In this study, Li 4 MoO 5 -LiFeO 2 binary system is targeted as a new high-capacity electrode material.…”

Study of the Failure Mechanisms of LiNi0.8Mn0.1Co0.1O2Cathode Material for Lithium Ion Batteries

“…19,22,23 However, to obtain such a capacity, these materials must be cycled over a wide potential range of 2.5-4.6 V (vs. Li + /Li), which may be challenging for the current carbonate-based electrolytes. Major issues such as large irreversible capacity (IRC), 19,33,34 voltage fade upon cycling 22,[35][36][37][38][39][40] and poor rate capability 22,41,42 have hindered the application of these materials. * Electrochemical Society Student Member.…”

Solid-state Redox Reaction of Oxide Ions for Rechargeable Batteries

“…37 Nevertheless, partial oxygen loss is also inevitable in this system, and in-plane superlattice ordering is lost after charge to the voltage plateau. 6,32,38,39 The oxidation of oxide ions results in partial oxygen loss, and tetravalent manganese ions are in part reduced to the trivalent state on the discharge after charge beyond the voltage plateau. 6,32,34 Moreover, similar to pure Li 2 MnO 3 , the electrode performance of the solid-solution samples highly depends on the particle size.…”

“…6,32,38,39 The oxidation of oxide ions results in partial oxygen loss, and tetravalent manganese ions are in part reduced to the trivalent state on the discharge after charge beyond the voltage plateau. 6,32,34 Moreover, similar to pure Li 2 MnO 3 , the electrode performance of the solid-solution samples highly depends on the particle size. The extent of oxygen loss vs. hole stabilization (and/or the formation of peroxide ions) is significantly influenced by the particle size.…”