Hierarchical nickel oxalate superstructure assembled from 1D nanorods for aqueous Nickel-Zinc battery

Hierarchical superstructures in nano/microsize can provide improved transport of ions, large surface area, and highly robust structure for electrochemical applications. Herein, a facile solution precipitation method is presented for synthesizing a hierarchical nickel oxalate (Ni-OA) superstructure composed of 1D nanorods under the control of mixed solvent and surfactant of sodium dodecyl sulfate (SDS). The growth process of the hierarchical Ni-OA superstructure was studied and indicated that the product had good stability in mixed solvent. Owing to smaller size, shorter pathway of ion diffusion, and abun-dant interfacial contact with electrolytes, hierarchical Ni-OA superstructure (Ni-OA-3) showed higher specific capacity than aggregated micro-cuboids (Ni-OA-1) and self-assembled micro/nanorods (Ni-OA-2). Moreover, the assembled Ni-OA-3//Zn battery showed good cyclic stability in aqueous electrolytes, and achieved a maximum energy density of 0.42 mWh cm-2 (138.75 Wh kg-1), and a peak power density of 5.36 mW cm-2 (1.79 kW kg-1). This work may provide a new idea for the investigation of hierarchical nickel oxalate-based materials for electrochemical energy storage. (c) 2022 Elsevier Inc. All rights reserved.

Automated summary

Hierarchical superstructures composed of 1D nanorods were synthesized using a facile solution precipitation method with the control of mixed solvent and sodium dodecyl sulfate (SDS) surfactant. The hierarchical nickel oxalate (Ni-OA) superstructure showed improved stability and higher specific capacity compared to aggregated micro-cuboids and self-assembled micro/nanorods. The assembled Ni-OA-3//Zn battery exhibited good cyclic stability and achieved a high energy density and peak power density in aqueous electrolytes. This work provides a new approach for investigating hierarchical nickel oxalate-based materials in electrochemical energy storage.