Enhanced Electrochemical and Thermal Stabilities of Li[Ni_0.88Co_0.09Al_0.03]O₂ Cathode Material by La₄NiLiO₈ Coating for Li–Ion Batteries

Abstract

Nickel-rich layered oxides with high reversible capacity are considered as the next-generation cathode materials for lithium-ion batteries (LIBs). However, capacity degradation induced by side reactions and structural degradation on the surface has been the main obstacle for their applications. In this work, a stable layer of La 4 NiLiO 8 is coated on Ni-rich material of Li[Ni 0.88 Co 0.09 Al 0.03 ]O 2 (NCA) by a facile method. The formation process of the La 4 NiLiO 8 layer is analyzed from both thermody-namic and dynamics aspects. The results indicate that oxygen migration evolution near the NCA surface is effectively reduced, thus improving the structural stability of the lattice and alleviating the side reactions on the surface. The electrochemical and thermal stabilities of NCA material are remarkably improved by coating the La 4 NiLiO 8 layer. This work provides a strategy for effective coating functional materials on Ni-rich cathode materials for LIBs.

Illustration of Capacity Fading Factors on the Example of La2(Li0.5Ni0.5)O4‐Modified High Nickel Layered Oxide Material

“…Prolonged cycling of LNP‐NCM_B sample shows both increased discharge capacity (comparing to other samples) and improved capacity retention, especially at elevated temperature. The positive effects of modifying by La 2 (Li 0.5 Ni 0.5 )O 4 ‐phase was reported previously and associated to facilitating the movement of lithium ions across electrode/electrolyte interface [34–41] …”

“…The positive effects of modifying by La 2 (Li 0.5 Ni 0.5 )O 4 -phase was reported previously and associated to facilitating the movement of lithium ions across electrode/electrolyte interface. [34][35][36][37][38][39][40][41] Nevertheless, modification of washed NCM powder (with the low content of LRC) by La 2 (Li 0.5 Ni 0.5 )O 4 doesn't improve noticeably electrode material performance in terms of capacity retention. At both temperature regimes we see high rate of capacity fading for LNP-NCM_W cells, which is around 85 % after 50 cycles (Figure 2c, d).…”

“…[35,36] Modification of layered oxide cathode materials by La 2 (Li 0.5 Ni 0.5 )O 4 and the reasons of capacity fading were presented in many literature sources. [36][37][38][39][40][41][42] The improved performance of LNP-coated cathodes is attributed to the enhancement of structural stability resulting from increased conductive properties (both electronic and ionic transport) of modified electrodes.…”

“…La 2 (La 0.5 Ni 0.5 )O 4 ‐phase is mainly formed by the reaction between La‐ and Ni‐containing species, on the surface of NCM during the heat‐treatment at high temperature in oxygen atmosphere [35,36] . Modification of layered oxide cathode materials by La 2 (Li 0.5 Ni 0.5 )O 4 and the reasons of capacity fading were presented in many literature sources [36–42] . The improved performance of LNP‐coated cathodes is attributed to the enhancement of structural stability resulting from increased conductive properties (both electronic and ionic transport) of modified electrodes.…”

The Improved Interfacial and Thermal Stability of Nickel‐Rich LiNi0.85Co0.10Mn0.05O2 Cathode in Li‐Ion Battery via Perovskite La4NiLiO8 Coating

“…In addition, in the XRD pattern, the obvious splitting of two groups of diffraction peaks, 006/012 and 108/110, indicates that the material has a good hexagonal structure [21] . Due to the coating thickness of La 4 NiLiO 8 is too thin, it is difficult to detect the results by XRD, so we coated a thick coating ratio, the characteristic peaks of La 4 NiLiO 8 (PDF52‐1671) were found in the thick coating proportion materials (Figure S1), it is proved that La 4 NiLiO 8 material is coated on the surface of NCM85, which is consistent with the results of scanning electron microscopy (SEM).…”