Inhibiting Mn Migration by Sb‐Pinning Transition Metal Layers in Lithium‐Rich Cathode Material for Stable High‐Capacity Properties

Abstract

Owing to the interacted anion and cation redox dynamics in Li2MnO3, the high energy density can be obtained for lithium‐rich manganese‐based layered transition metal (TM) oxide [Li1.2Ni0.2Mn0.6O2, LNMO]. However, irreversible migration of Mn ions and oxygen release during highly de‐lithiation can destroy its layered structure, leading to voltage and capacity decline. Herein, non‐TM antimony (Sb) is pinned to the TM layer of LNMO by a facile sol‐gel method. High‐resolution ex and in situ characterization technologies manifest that the introduction of trace Sb inhibits the migration of Mn ions, forming a more stable structure. Sb can impressively adjust the Mn‐O interaction between anions and cations, beneficial to decrease the energy level of Mn 3d and O 2p orbitals and expand their band gap according to the theoretical calculation results. As a result, the discharge specific capacity and the energy density for SbLi1.2[Ni0.2Mn0.6]O2 (SLNMO) reaches as high as 301 mAh g−1 and 1019.6 Wh kg−1 at 0.1 C, respectively. Moreover, the voltage decay is reduced by 419.8 mV compared with LNMO. The regulative interaction between Mn 3d and isolated O 2p bands provides an accurate guidance for solving electrochemical performance deficiencies of lithium‐rich manganese‐based cathode oxide.

Anion–Cation Dual-Ion Multisite Doping Stabilizes the Crystal Structure of Li-Rich Layered Oxides

“…The calculated density of states (DOS) reflects the influence of Mg/S codoping on the electronic structure of TM 3d and O 2p orbitals, as shown in Figure b. Compared to PLLO, MSLLO exhibits a reduced energy for TM 3d–O 2p and isolated O 2p bands, indicating that Mg/S codoping can enhance oxygen stability at high voltages. , The state energy of TM 3d and O 2p orbitals is critical for determining the redox voltage, and the lower state energy in MSLLO results in a higher operating voltage, as illustrated in Figures d,g.…”

“…Compared to PLLO, MSLLO exhibits a reduced energy for TM 3d−O 2p and isolated O 2p bands, indicating that Mg/S codoping can enhance oxygen stability at high voltages. 40,41 The state energy of TM 3d and O 2p orbitals is critical for determining the redox voltage, 42 and the lower state energy in MSLLO results in a higher operating voltage, as illustrated in Figures 4d,g. Based on the above discussion, we employed Figure 8c to clarify the underlying mechanism through which Mg/S codoping enhances the stability of LLOs' crystal structure.…”

Morphology-Tuned Porous Lithium-Rich Cathode Materials Synthesized via a Solvothermal Approach for Li-Ion Battery Application

“…To address the aforementioned issues, various strategies have been applied, such as surface-coating modification, − heteroatom doping, − preactivation, structure regulation (such as transition-metal elemental gradient design, , defect regulation, , morphology and size control, , etc.). Meanwhile, the structure regulation by different synthesis processes mentioned above is an essential way to improve its intrinsic electrochemical performance.…”

“…Meanwhile, the structure regulation by different synthesis processes mentioned above is an essential way to improve its intrinsic electrochemical performance. Notably, the porous structure has been proven effective in improving the active contact interface between cathode material and electrolyte and shortening the lithium ion diffusion pathway in bulk particles, contributing to faster electrochemical kinetics and outstanding rate performance. ,− On the other hand, the higher contact interface can also aggravate the side reaction, leading to the pulverization of cathode particles, which could be suppressed by structural engineering and homogeneous particle size distribution. Inspired by the abovementioned information, we can fulfill this target by the rigorous regulation of precursors of oxide cathode materials, which would significantly impact the derived active materials due to the topological effect of the structure. − …”

Bi-directional strains increase the performance of iridium oxide nanoparticles towards the acidic oxygen evolution reaction in proton exchange membrane electrolyzers

“…30 In this study, we focused on harnessing the unique characteristics of the transition metal antimony (Sb), known for its characteristic d 10 orbital electron arrangement and high stability, along with its abundant and cost-effective global reserves. [31][32][33] Our goal was to synthesize a series of Sb m Ir 1−m O x @TB-IrO x core-shell nanoparticle catalysts with TBs using a fast pyrolysis method, while incorporating additional Sb into IrO x . The resulting catalysts displayed exceptional performance for the acidic OER, with Sb 0.3 Ir 0.7 O x @TB-IrO x proving to be the most remarkable, exhibiting a significantly low overpotential of 201 mV at a current density of 10 mA cm −2 .…”