Abstract
Electrochemical energy storage devices have been the attractive solution to the energy storage demand of the future energy internet action, and the strong efforts are greatly needed for the development of novel electrode materials together with the advanced electrode architecture. Although the transition metal oxides that have been extensively studied, especially in the form of nanoparticles, from the viewpoint of surface electrochemistry, these nano-oxides suffer from the severe side reaction between electrode and electrolyte, as well as the aggregation due to the high surface energy, leading to the high level of electrochemical irreversibility and poor cyclability. Therefore, the transition metal compounds-based nanoarrays electrodes emerges recently to provide electrochemical energy storage with approach to achieve cost, life, performance and even environment targets. Herein, Co3O4@Co3S4@nickel foam, NiCo2O4@Ni3S2@nickel foam, and CoNi2S4@ppy@Nitrogen-doped graphene nanoarrays have been studied for the flexible asymmetric pseudocapacitors applications, which demonstrate competitive energy storage properties for portable electronics; NiCo2S4@Mo2S4@CT nanoarrays with hierarchical structure have been studied for high-energy-density sodium ion batteries, offering the potential low cost pproach for electric vehicles application; NiCo2S4@CT nanoarrays have been demonstrated as the high-performance catalyst in the lithium sulfur batteries, which may penetrated deeply in the multitude of applications ranging from the coin cells to large-scale energy storage station. Compared to the conventional double layer electric capacitor, our pseudocapacitor can offer 10 folds higher capacitance in the aqueous electrolyte. Moreover, the sodium ion battery designed here can stably charge/discharge for 400 cycles at 3.2 A g-1. In addition, our high-performance lithium sulfur battery achieves ~1600 mAh g-1 at 0.1 C and the utra-stable cyclability at 0.5 C with a low decay rate of 0.02%/cycle. All in all, the research projects are set to contribute incremental knowledge and understanding of nanostructured materials to move the technology forward. One the one hand, the growth mechanism that drives the nucleation and morphological evolution of nanostructured materials has been deeply studied. On the other hand, the application of nanostructured materials has been explored, ranging from supercapacitor, sodium ion battery, to lithium sulfur battery, and the prominent electrochemical performance has been achieved.