Cathode of Zn-Ni Layered Double Hydroxide Nanosheet Arrays Wrapped with a Porous NiMoS x Shell and Anode of 3D Hierarchical Nitrogen-Doped Carbon for High-Performance Asymmetric Supercapacitors

• Published in: ACS applied energy materials 2021-09, Vol.4 (9), p.9166-9177
• Main Authors: Lee, Myeong Hun, Bandyopadhyay, Parthasarathi, Jin, En Mei, Baasanjav, Erdenebayar, Kang, Dong-Won, Jeong, Sang Mun
• Format: Article
• Language: English
• ISSN: 2574-0962; 2574-0962
• DOI: 10.1021/acsaem.1c01412

The rational design and synthesis of multicomponent core@shell structures with fine morphology is a promising approach to develop electrode materials for advanced supercapacitors. In this study, Zn-Ni LDH@NiMoS x nanosheets with a hierarchical heterostructure are grown in situ on nickel foam through the hydrothermal routes, for the potential use as an integrated positive electrode material. The Zn-Ni LDH@NiMoS x shows a unique morphology and mesoporous feature with excellent synergistic effects between individual components. Compared to the single components of Zn-Ni LDH and NiMoS x , the Zn-Ni LDH@NiMoS x nanosheet arrays show better specific capacity (357.88 mA h g–1 at a current of 5 mA cm–2) and rate performance. Meanwhile, ZIF-8 derived 3D nanoporous N-doped carbon (ZPNC) material is used as an negative electrode material with high surface area (918.3 m2 g–1), excellent capacity (52.42 mA h g–1 at 2 mA cm–2), and rate performance (∼55% at 50 mA cm–2). The asymmetric supercapacitor device based on Zn-Ni LDH@NiMoS x and ZPNC electrodes exhibits a specific capacity of 73.18 mA h g–1 at 3.5 mA cm–2 and an excellent cycle lifespan of 90% after 6000 cycles. The device also demonstrates excellent energy density (58.54 W h kg–1) and very high power density (7397.34 W kg–1).