A controllable preparation of two-dimensional cobalt oxalate-based nanostructured sheets for electrochemical energy storage

• Published in: Chinese chemical letters Vol. 33; no. 6; pp. 3249 - 3254
• Main Authors: Sun, Fancheng, Li, Qing, Bai, Yang, Zhang, Guangxun, Zheng, Shasha, Peng, Maoying, Chen, Xudong, Lin, Nuo, Pang, Huan
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.06.2022; School of Chemistry and Chemical Engineering,Institute for Innovative Materials and Energy,Yangzhou University,Yangzhou 225009,China
• Subjects: Capacity; Co3O4; Cobalt oxalate; Energy storage; Two-dimensional nanosheets; Two-dimensional nanosheets; Cobalt oxalate; Capacity; Co3O4; Energy storage
• ISSN: 1001-8417; 1878-5964
• DOI: 10.1016/j.cclet.2021.10.075

Well-defined two-dimensional (2D) cobalt oxalate (CoC2O4·2H2O) nanosheets exhibit more excellent property than common bulk cobalt oxalate due to high specific surface areas and high-efficient transport of ion and electron. However, the delicate control of the 2D morphology of CoC2O4·2H2O during their synthesis remains challenging. Herein, 2D CoC2O4·2H2O nanosheets (M1), grown by straightforward chemical precipitation, can be tuned from three-dimensional (3D) structure during their synthesis with no templates or capping agents. This control is obtained by rationally changing the ratio of reactants with ethylene glycol as solvent. Moreover, Co3O4/CoC2O4 composites (M1-250) have been fabricated through low-temperature thermal treatment of the M1 precursor in air, which possess porous surfaces with the 2D morphology maintained. Benefiting from the porous surfaces, more redox-active sites and better electrical conductivity of Co3O4, the constructed M1-250//AC aqueous device manifest improved kinetics of the electrochemistry process with energy density of 27.9 Wh/kg at 550.7 W/kg and good cycling stability with sustaining 73.0 mAh/g after 5000 cycles. [Display omitted] The 2D nanostructured cobalt oxalate-based electrode materials were controllably synthesized by straightforward chemical precipitation and low-temperature thermal transformation treatment, which were applied to electrochemical energy storage.