A High-Capacity Anode for Lithium Batteries Consisting of Mesoporous NiO Nanoplatelets

• Published in: Energy & fuels 2013-09, Vol.27 (9), p.5545-5551
• Main Authors: Caballero, A, Hernán, L, Morales, J, González, Z, Sánchez-Herencia, A.J, Ferrari, B
• Format: Article
• Language: English
• Subjects: Crystallites; Cycles; Electrodes; Lithium batteries; Nanostructure; Surface layer; Texture; Two dimensional
• ISSN: 0887-0624; 1520-5029
• DOI: 10.1021/ef400797r

The two-dimensional (2D) nanostructures of NiO obtained after calcination at 450 °C of β-Ni(OH)2, which is a product of the sonocrystallization of Ni precursors with the aid of an organic modifier, was studied as an electrode for Li-ion batteries. Two outstanding properties that have not yet been reported for this oxide are described: (i) an unusual high specific capacity (ca. 1100 mAh g–1 at the second cycle), which notably exceeds its theoretical capacity (718 mAh g–1); and (ii) a continuous increase of the capacity on cycling (ca. 1500 mAh g–1 at the 30th cycle). We assign this extra capacity to the reversibility of side reactions undergone by the electrolyte on forming the solid electrolyte interface (SEI). We believe that the mesoporous texture of the NiO-platelet-like particles and their special microstructural properties are responsible for this unexpected electrochemical behavior. In fact, electrodes made of commercial nonporous NiO, with higher crystallite size and low microstrain content, lack these unusual properties. Its capacity at the second cycle was only 460 mAh g–1, and it was significantly reduced during cycling, with the value at the 30th cycle barely reaching 25 mAh g–1.