Porous Co₃O₄ Nanosheets with Extraordinarily High Discharge Capacity for Lithium Batteries

Abstract

In this work, we report the simple solid-state formation of porous Co3O4 with a hexagonal sheetlike structure. The synthesis is based on controlled thermal oxidative decomposition and recrystallization of precursor Co(OH)2 hexagonal nanosheets. After thermal treatment, the hexagonal sheetlike morphology can be completely preserved, despite the fact that there is a volume contraction accompanying the process: Co(OH)2-->Co3O4. Because of the intrinsic crystal contraction, a highly porous structure of the product is simultaneously created. Importantly, when evaluated as electrode materials for lithium-ion batteries, the as-prepared porous Co3O4 nanosheets exhibit superior Li-battery performance with good cycle life and high capacity (1450 mAh g(-1)) due to their porous sheetlike structure and small size. As far as we know, the performance of the Co3O4-based anode materials for lithium batteries presented here is the best up to now. Considering the improved performance and cost-effective synthesis, the as-prepared porous Co3O4 nanosheets might be suitable as anode electrodes for next-generation lithium-ion batteries.

Evaluating the performance of nanostructured materials as lithium-ion battery electrodes

“…Although the unique structuring enabled high capacity at relatively low rates, the nanobelts ultimately suffered from poor rate performance, with stable capacities only obtained at C-rate [195]. Other recent examples of Co3O4 nanostructures demonstrated include nanosheets [196], multi-shelled hollow spheres [197] and octahedral nanocages [198]. Of these examples, the 2D nanosheet structures prepared by Zhan et al [196], offered considerable capacity, to as much as 1450 mA h g -1 at the 27 th cycle (end of test).…”

“…Other recent examples of Co3O4 nanostructures demonstrated include nanosheets [196], multi-shelled hollow spheres [197] and octahedral nanocages [198]. Of these examples, the 2D nanosheet structures prepared by Zhan et al [196], offered considerable capacity, to as much as 1450 mA h g -1 at the 27 th cycle (end of test). The hydrothermal treatment, resulting in the transformation of Co(OH)2 nanosheets to Co3O4 nanosheets, subsequently attained porosity as a result of the structural contraction during formation.…”

Mixed Colloidal Suspensions of Reduced Graphene Oxide and Layered Metal Oxide Nanosheets: Useful Precursors for the Porous Nanocomposites and Hybrid Films of Graphene/Metal Oxide

“…[1][2][3] Currently, research activity on the nanostructured materials has extended to 2D nanostructures such as nanosheets and nanoplates. [3][4][5] One of the most useful chemical methods to synthesize 2D nanosheets is an exfoliation of layered inorganic solids into individual layers. [6][7][8] The exfoliated 2D nanosheets are obtained in the form of a stable colloidal suspension in aqueous media or organic solvent.…”

“…[28] Electrochemical measurements of LGM nanocomposites: The electrochemical activity of the Li/RGO-layered MnO 2 nanocomposites was tested by carrying out cyclic voltammetry (CV) measurements. The CV data of the Li/RGO-layered MnO 2 nanocomposites collected with the aqueous solution of 1.0 m Na 2 SO 4 and the scan rate of 20 mV s À1 are plotted in Figure 8. Regardless of the content of RGO nanosheets, all of the present nanocomposites exhibited pseudocapacitance-type CV data without distinct redox peaks.…”

Electrospun Hierarchical CaCo2O4 Nanofibers with Excellent Lithium Storage Properties

“…[17][18][19] However, the practical use of Co-based oxides has been hindered by their poor cycling performance and fast capacity fading. [20,21] Part of the problem may be associated with significant volume changes and the aggregation of nanograins during lithium insertion/extraction, which may lead to the loss of electrical contact in electrode. [22,23] In attempts to improve the cycling performance of Co-based oxides, the design of active/inactive matrices, including carbon [24,25] and MO x (Zn, Fe, Mn, [26][27][28][29][30][31][32][33] With this in mind, Ca-Co-based ternary oxides with suitable morphology and structure could be desirable as anode materials for LIBs, in which the inactive CaO matrix generated during electrochemical cycling processes could not only buffer the volume change, but also prevent the aggregation of active material, resulting in improved cycling performance.…”