Understanding the electrochemical superiority of 0.6Li[Li 1/3 Mn 2/3 ]O 2 -0.4Li[Ni 1/3 Co 1/3 Mn 1/3 ]O 2 nanofibers as cathode material for lithium ion batteries

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

Li-rich manganese-based layered cathode Li_1.2Mn_0.54Ni_0.13Co_0.13O₂ (LMNCO) nanotubes are synthesized by electrospinning and surface coated with different amounts of amorphous Al₂O₃.

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

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 Li₂MnO₃ 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^-1) 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^-1 can still be obtained. The favorable results can assist in developing the LLO material with outstanding electrochemical properties.

Enhanced Electrochemical Properties of Zr4+-doped Li1.20[Mn0.52Ni0.20Co0.08]O2 Cathode Material for Lithium-ion Battery at Elevated Temperature

The typical co-precipitation method was adopted to synthesized the Li-excess Li_1.20[Mn_0.52-xZr _x Ni_0.20Co_0.08]O₂ (x = 0, 0.01, 0.02, 0.03) series cathode materials. The influences of Zr⁴⁺ doping modification on the microstructure and micromorphology of Li_1.20[Mn_0.52Ni_0.20Co_0.08]O₂ cathode materials were studied intensively by the combinations of XRD, SEM, LPS and XPS. Besides, after the doping modification with zirconium ions, Li_1.20[Mn_0.52Ni_0.20Co_0.08]O₂ cathode demonstrated the lower cation mixing, superior cycling performance and higher rate capacities. Among the four cathode materials, the Li_1.20[Mn_0.50Zr_0.02Ni_0.20Co_0.08]O₂ exhibited the prime electrochemical properties with a capacity retention of 88.7% (201.0 mAh g^-1) after 100 cycles at 45 °C and a discharge capacity of 114.7 mAh g^-1 at 2 C rate. The EIS results showed that the Zr⁴⁺ doping modification can relieve the thickening of SEI films on the surface of cathode and accelerate the Li⁺ diffusion rate during the charge and discharge process.