Enhanced Capacity of NiO Nanocubes with High Dispersion and Exposed Facets Reinforced by Thermal Plasma

Structure architectonics have a great effect on the electrochemical performance for conversion mechanism materials because they face inevitable big volume changes and serious agglomeration during the lithiation/delithiation process, subsequent to particle cracking and electrode pulverization. Here, we report a simple method for the scalable preparation of ultrafine NiO nanocubes (∼500 g h–1) with high dispersion and exposed crystal facets reinforced by thermal plasma. In situ transmission electron microscopy observation and density functional theory calculation reveal that NiO nanocubes could not only enable stable morphology and small volume expansion (56%) at full lithiation but also facilitate Li-ion transportation. These characteristics result in improved cycling performance and enhanced rate capability. More importantly, during the lithiation process, ultrafine Ni particles were formed. The Ni particles may catalyze the decomposition of the irreversible Li ion in the solid electrolyte interlayer and lead to increased capacity. Using as Li-ion-battery anodes, the as-synthesized NiO nanocubes show an impressive electrochemical performance: high capacity for long cycles (>1000 mAh g–1; 600 cycles), improved Coulombic efficiency (>99%), and superior rate properties. This work provides a visualized result for exploring the atomic-scale structure evolution of NiO during the lithiation process and is hoped to be a guide for the development of advanced conversion mechanism materials with higher performance.