Crystal-match guided formation of single-crystal tricobalt tetraoxygen nanomesh as superior anode for electrochemical energy storage

Abstract

In this article, we introduce a novel two-dimensional (2D) functional Co₃O₄ nanostructure, “nanomesh”, which possesses the highest surface area (382 m² g⁻¹) as compared to the other Co₃O₄ nanostructures, well-crystallized features, thickness of no more than 10 nm and a void space diameter below 6.0 nm. These structural characteristics of the nanomesh are well-suited for lithium-ion battery (LIBs) applications. In initial tests, high specific capacity (1800 mAh/g), good rate capability (above 380 mAh/g at a discharging rate of 1000 mA g⁻¹ over 50 cycles) and stable cyclability (up to 100 cycles) have been demonstrated. In addition, the dominant (12) crystal plane in the nanomesh has much higher surface energy than the conventional (111) and (100) crystal planes, leading to higher activity in supercapacitors. The Co₃O₄ nanomesh demonstrated in this research could be successfully utilized in energy and environmental applications, such as selective catalysis, gene delivery and gas or biological sensing, besides the application in electrochemical energy storage shown in this work. More importantly, the synthesis strategy used in this research can possibly be extended to other material systems as a general approach to fabricate 2D mesoporous oxides.