Synthesis of 2D/2D Structured Mesoporous Co3O4 Nanosheet/N-Doped Reduced Graphene Oxide Composites as a Highly Stable Negative Electrode for Lithium Battery Applications

Palanichamy Sennu; Hyo Sang Kim; Jae Youn An; Vanchiappan Aravindan; Yun-Sung Lee

doi:10.1002/asia.201500466

Synthesis of 2D/2D Structured Mesoporous Co3O4 Nanosheet/N-Doped Reduced Graphene Oxide Composites as a Highly Stable Negative Electrode for Lithium Battery Applications

Chem Asian J. 2015 Aug;10(8):1776-83. doi: 10.1002/asia.201500466. Epub 2015 Jun 29.

Authors

Palanichamy Sennu¹, Hyo Sang Kim¹, Jae Youn An¹, Vanchiappan Aravindan², Yun-Sung Lee³

Affiliations

¹ Faculty of Applied Chemical Engineering, Chonnam National University, Gwang-ju, 500-757, Republic of Korea.
² Energy Research Institute@NTU (ERI@N), Nanyang Technological University, Research Techno Plaza, 50 Nanyang Drive, Singapore, 637553, Singapore.
³ Faculty of Applied Chemical Engineering, Chonnam National University, Gwang-ju, 500-757, Republic of Korea. leeys@chonnam.ac.kr.

PMID: 26033848
DOI: 10.1002/asia.201500466

Abstract

Mesoporous Co3O4 nanosheets (Co3 O4 -NS) and nitrogen-doped reduced graphene oxide (N-rGO) are synthesized by a facile hydrothermal approach, and the N-rGO/Co3O4 -NS composite is formulated through an infiltration procedure. Eventually, the obtained composites are subjected to various characterization techniques, such as XRD, Raman spectroscopy, surface area analysis, X-ray photoelectron spectroscopy (XPS), and TEM. The lithium-storage properties of N-rGO/Co3O4 -NS composites are evaluated in a half-cell assembly to ascertain their suitability as a negative electrode for lithium-ion battery applications. The 2D/2D nanostructured mesoporous N-rGO/Co3O4 -NS composite delivered a reversible capacity of about 1305 and 1501 mAh g(-1) at a current density of 80 mA g(-1) for the 1st and 50th cycles, respectively. Furthermore, excellent cyclability, rate capability, and capacity retention characteristics are noted for the N-rGO/Co3O4 -NS composite. This improved performance is mainly related to the existence of mesoporosity and a sheet-like 2D hierarchical morphology, which translates into extra space for lithium storage and a reduced electron pathway. Also, the presence of N-rGO and carbon shells in Co3O4 -NS should not be excluded from such exceptional performance, which serves as a reliable conductive channel for electrons and act as synergistically to accommodate volume expansion upon redox reactions. Ex-situ TEM, impedance spectroscopy, and XPS, are also conducted to corroborate the significance of the 2D morphology towards sustained lithium storage.

Keywords: cobalt; electrochemistry; lithium-ion batteries; mesoporous materials; nanostructures.