Effects of Nanofiber Architecture and Antimony Doping on the Performance of Lithium-Rich Layered Oxides: Enhancing Lithium Diffusivity and Lattice Oxygen Stability

Abstract

Li-rich layered oxides (LLOs) with high specific capacities are favorable cathode materials with high-energy density. Unfortunately, the drawbacks of LLOs such as oxygen release, low conductivity, and depressed kinetics for lithium ion transport during cycling can affect the safety and rate capability. Moreover, they suffer severe capacity and voltage fading, which are major challenges for the commercializing development. To cure these issues, herein, the synthesis of high-performance antimony-doped LLO nanofibers by an electrospinning process is put forward. On the basis of the combination of theoretical analyses and experimental approaches, it can be found that the one-dimensional porous micro-/nanomorphology is in favor of lithium-ion diffusion, and the antimony doping can expand the layered phase lattice and further improve the lithium ion diffusion coefficient. Moreover, the antimony doping can decrease the band gap and contribute extra electrons to O within the LiMnO phase, thereby enhancing electronic conductivity and stabilizing lattice oxygen. Benefitting from the unique architecture, reformative electronic structure, and enhanced kinetics, the antimony-doped LLO nanofibers possess a high reversible capacity (272.8 mA h g) and initial coulombic efficiency (87.8%) at 0.1 C. Moreover, the antimony-doped LLO nanofibers show excellent cycling performance, rate capability, and suppressed voltage fading. The capacity retention can reach 86.9% after 200 cycles at 1 C, and even cycling at a high rate of 10 C, a capacity of 172.3 mA h g can still be obtained. The favorable results can assist in developing the LLO material with outstanding electrochemical properties.

Al2O3-coated Li1.2Mn0.54Ni0.13Co0.13O2 nanotubes as cathode materials for high-performance lithium-ion batteries

“…Moreover, the intensity ratio of the (003) and (104) peaks is relevant to the cationic mixing degree. 24 With increasing Al 2 O 3 content, the value of I (003) /I (104) decreased from 1.88 to 1.26, but the value of I (003) /I (104) for all samples are greater than 1.2, which indicates both materials suppressed cation mixing.…”

“…The Mn 2p 3/2 , Ni 2p 3/2 and Co 2p 3/2 peaks of two samples are located at 642.5 eV, 780.8 eV and 855.1 eV, indicating that the chemical valences of Mn, Co and Ni are +4, +3 and +2, respectively. 24,25 Additionally, a peak appearing around 73.8 eV (Fig. 4d) can only be observed in S-LMNCO sample, which is corresponding to the Al 2p 3/2 BE obtained in Al 2 O 3 .…”

High-Performance Lithium-Rich Layered Oxide Material: Effects of Preparation Methods on Microstructure and Electrochemical Properties

“…The major peaks in the XRD pattern could be indexed based on α-NaFeO 2 layered structure with space group R3m and monoclinic symmetry with space group C2/m [32]. The (006)/(012) peak and (018)/(110) peak can be clearly distinguished, indicating that the material is a typical layered structure [41]. The lattice parameters of the prepared samples were analyzed via JADE6.0, as shown in Table 1.…”

Oxygen Release Degradation in Li‐Ion Battery Cathode Materials: Mechanisms and Mitigating Approaches

“…Schematic representation of the chemical composition modification approaches used to improve the structural stability of the cathode materials. A) Atomic structure of a cationic doped layered oxide cathode: Reproduced with permission . Copyright 2018, American Chemical Society.…”