Enhancing the Thermal and Upper Voltage Performance of Ni-Rich Cathode Material by a Homogeneous and Facile Coating Method: Spray-Drying Coating with Nano-Al₂O₃

Abstract

The electrochemical performance of Ni-rich cathode material at high temperature (>50 °C) and upper voltage operation (>4.3 V) is a challenge for next-generation lithium-ion batteries (LIBs) because of the rapid capacity degradation over cycling. Here we report improved performance of LiNi0.8Co0.15Al0.05O2 materials via a LiAlO2 coating, which was prepared from a Ni0.80Co0.15Al0.05(OH)2 precursor by spray-drying coating with nano-Al2O3. Investigations by X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and transmission electron microscopy revealed that an Al2O3 layer is uniformly distributed on the precursor and a LiAlO2 layer on the as-prepared cathode material. Such a coating shell acts as a scavenger to protect the cathode material from attack by HF and serious side reactions, which remarkably enhances the cycle performance at 55 °C and upper operating voltage (4.4 and 4.5 V). In particular, the sample with a 2% Al2O3 coating shows capacity retentions of 90.40%, 85.14%, 87.85%, and 81.1% after 150 cycles at a rate of 1.0C at room temperature, 55 °C, 4.4 V, and 4.5 V, respectively, which are significantly higher than those of the pristine one. This is mainly due to the significant improvement of the structural stability led by the effective coating technique, which could be extended to other cathode materials to obtain LIBs with enhanced safety and excellent cycling stability.

Enhanced Electrochemical and Thermal Stabilities of Li[Ni0.88Co0.09Al0.03]O2 Cathode Material by La4NiLiO8 Coating for Li–Ion Batteries

“…However, insufficient energy density due to the limited lithium utilization (<60 %) in the structure of LCO, as well as the high cost of cobalt, restricts its broad applications in stationary energy storage and electric vehicles (EVs) . Hence, intensive researches have been implemented, which focus on developing alternative cathode materials with higher lithium utilization and larger energy density, to expand the application field of LIBs . Furthermore, LIBs for grid‐level energy storage and EVs are expected to offer low cost, superior safety and fast charging .…”

Anti‐Oxygen Leaking LiCoO2

“…In this context, synthesis of high surface area structures such as nanorod arrays or porous nanosheet 3D structures of LiCoO 2 have been carried out to achieve fast intercalation kinetics and flexible Li‐ion batteries. However, since many degradation mechanisms including the parasitic oxygen release reaction, are surface and subsurface originated, various approaches such as coating, surface passivation, synthesis of core–shell structures and chemical gradient compositions have been pursued for improving the cyclability and stability of cathode materials. For instance, it has been shown that coating the LiCoO 2 cathodes with Al, F‐based material that forms a Li‐Co‐Al‐F‐O solid solution beneath the surface can improve the structural stability of LCO when operating at 4.6 V. Similarly, AlPO 4 coating on LiCoO 2 has shown to effectively prevent the oxygen release reaction and inhibit the over‐charge induced thermal runaway reaction .…”

LiNi0.8Co0.15Al0.05O2: Enhanced Electrochemical Performance From Reduced Cationic Disordering in Li Slab

“…It is reported that the use of surface modification methods (LiCo 2 9, 10 , Al 2 O 3 11 , LiMnPO 4 3 , ZnO 12 , FeF 3 13 , TiO 2 14 ,) can effectively solve the above-mentioned problems. The coating layer prevents the contact of the active material with the electrolyte.…”