Hierarchical core@shell ZnCo LDH@Ni3S2 on nickel foam for high performance asymmetric supercapacitors

Core-shell nanostructured compounds have been investigated as encouraging electrodes for supercapacitors because of their high electrical conductivity and easy access to active sites. In this work, a hierarchical ZnCo LDH@Ni3S2 core@shell nanostructure has been synthesized using a simple method. The ZnCo LDH@Ni3S2 showed excellent capacity (1069C g-1 at 2 A g-1), considerable rate performance, and good durability, which is superior to those of the ZnCo LDH and Ni3S2 individual electrodes. In addition, an asymmetric supercapacitor has been prepared using ZnCo LDH@Ni3S2 and activated carbon as the positive and negative electrodes, respectively. The asymmetric supercapacitor exhibited a 39 W h kg- 1 maximum energy density at 423 W kg- 1 power density, 87 % of the initial capacity being retained after 5000 cycles. Moreover, the electrochemical performance of the hybrid supercapacitor fabricated can be enhanced by the synergism between the active materials. This study provides a good strategy for core@shell structure design of ZnCo LDH electrode combined with Ni3S2 modification. Additionally, it also improves electrochemical performance and achieves to high energy and power.