Mitigating voltage and capacity fading of lithium-rich layered cathodes by lanthanum doping

Abstract

La-doped lithium-rich layered oxide material Li1.2Mn0.54-xNi0.13Co0.13LaxO2 (x = 0.01, 0.02, 0.03) is firstly synthesized via a solvothermal method and subsequent high-temperature calcination technique. The effects of La substitution for partial Mn on the structure and electrochemical performance of materials are systematically studied by inductively coupled plasma optical emission spectroscopy (ICP-OES), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscope (EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and electrochemical measurement. The results reveal that La is effectively and homogenously doped into the materials, which can expand pathway for intercalation/deintercalation of Li + ions. In addition, owing to La doping, the Li1.2Mn0.52Ni0.13Co0.13La0.02O2 sample exhibits 93.2% capacity retention after 100 cycles at 1 C. More importantly, this doping can effectively restrain the decrease of

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

“…The oxidation peak around 4.0 V is relevant to the oxidation of Ni 2+ to Ni 4+ and Co 2+ to Co 3.6+ , and another oxidation peak around 4.6 V owing to removal of oxygen from Li 2 MnO 3 component and further oxidation of Co 3.6+ to Co 4+ . 33,34 Obviously, the S-LMNCO-4 sample has a higher peak at 4.6 V, suggesting a higher Li + transfer rate between Li 2 MnO 3 and layered component. The disappearance of oxidation peak at 4.6 V in the second cycle indicates the activation of the Li 2 MnO 3 is suppressed and the loss of oxygen from Li 2 MnO 3 is irreversible.…”

Insight of a Phase Compatible Surface Coating for Long‐Durable Li‐Rich Layered Oxide Cathode

“…Efforts to overcome these specific problems have been focused on the Li 1.2 Ni 0.13 Co 0.13 Mn 0.54 O 2 material as a result of its particularly high specific capacity and good cyclability . The strategies employed to improve the performance of Li‐rich layered oxides (LLOs) can be broadly classified into three groups: particle size control, lattice doping, and surface modification . Although nanosizing has been successfully used to increase the capacity and rate performance of LLOs, the resulting increased surface energy and area of the material along with decreased density lead to agglomeration of the material as well as severe side reaction with the electrolyte .…”

Insight into the capacity fading of layered lithium-rich oxides and its suppression via a film-forming electrolyte additive

“…The former decomposition products increase the interfacial resistance and battery internal pressure, while the latter accelerates the structural transformation of the LLO. [17][18][19][20][21][22] Great efforts to improve the structural and cycling stability of LLOs have been made, including surface coating (such as with Al 2 O 3 , ZrO 2 , AlF 3 , CaF 2 and polyaniline), [23][24][25][26][27] Na, K, La and Mg element doping [28][29][30][31] and the application of lm-forming electrolyte additives. [32][33][34][35][36] The usage of a lm-forming electrolyte additive, in comparison with the other methods, has the advantages of simple operation, high performance, and costeffectiveness, 37 and the additive works by decomposing before the carbonate-based electrolyte to generate a solid electrolyte interface (SEI) lm on the high voltage electrode surface.…”