Bifunctional ZnMn2O4/reduced graphene oxide microspheres with a needle-like surface architecture as effective electrodes for energy storage

• Published in: New journal of chemistry 2023-05, Vol.47 (21), p.10061-10069
• Main Authors: Pitcheri, Rosaiah, Guru Prakash Nunna, Merum, Dhananjaya, Bandar Ali Al-Asbahi, Sangaraju, Sambasivam, Uppala, Chalapathi, Si-Hyun, Park
• Format: Article
• Language: English
• Subjects: Current density; Cycles; Electrode materials; Electrodes; Energy storage; Graphene; Lithium-ion batteries; Microspheres; Process parameters; Rechargeable batteries; Synthesis; Zinc compounds
• ISSN: 1144-0546; 1369-9261
• DOI: 10.1039/d3nj00978e

The synthesis of bifunctional electrode materials is of tremendous interest for energy storage applications. A simple hydrothermal route is chosen to develop reduced graphene oxide encapsulated zinc manganite microspheres (ZnMn2O4/rGO). Microspheres with a needle-like surface architecture could be produced by carefully regulating the process parameters during synthesis and post-annealing. The ZnMn2O4/rGO composite exhibited a specific surface area of 67.82 m2 g−1. The ZnMn2O4/rGO composite electrode demonstrated bifunctional behavior for both lithium-ion batteries and supercapacitors. As an anode, it displayed exceptional discharge/charge capacity of 1578/1012 mA h g−1 at a current density of 0.1 A g−1 and maintained stable cycling behavior even after 300 cycles at a current density of 1 A g−1. Moreover, it showed excellent capacitive behavior with a specific capacity of 100.5 mA h g−1 at 1 A g−1 and maintained a cycling stability of 83% at 2 A g−1 even after 5000 cycles. Therefore, ZnMn2O4/rGO composites are promising candidates for practical applications in energy storage.