Hierarchical Nickel Sulfide Coated Halloysite Nanotubes For Efficient Energy Storage

- An integration strategy was presented to construct Ni3S2 based hierarchical composite.
- Nanowhisker Ni3S2 were densely integrated onto halloysite nanotubes.
- The well-designed electrode exhibits remarkable capacitance and cycling stability.
- This strategy provides good reference to electrode materials design for energy storage

Cost-effective and robust energy storage systems have attracted great attention for portable electronic devices. Three-dimensional electrodes can effectively enhance the charge transfer, increase the mechanical stability and thus improve the electrochemical performance upon continuous charge-discharge. The earth abundant halloysite nanotubes (HNTs) have shown immense potential in constructing nanoarchitectural composites. Here, we first demonstrate the development of hybrid composite of nickel sulfide (Ni3S2) and HNTs with glucose as binders for efficient energy storage in supercapacitor. The surface sulfhydrylation of HNTs and glucose-assisted hydrothermal reaction are crucial for the preparation of well-structured composite. Due to the synergistic effect between components, the Ni3S2/HNTs@HS composite electrode delivers a capacity of 450.4C g−1 and high retention of 82.6% over 2000 cycles in three-electrode supercapacitors. Moreover, the Ni3S2/HNTs@HS//Whatman paper//Ni3S2/HNTs@HS two-electrode symmetric supercapacitor exhibits a maximum potential window of 1.3 V, with a capacity of 250C g−1 and performance loss of only 18.2% over 2000 cycling at 1 A g−1. A maximum energy density of 79.6 Wh kg−1 is achieved at a power density of 1.03 kW kg−1. Such excellent energy storage performance suggests the great potential of Ni3S2/HNTs@HS for high-efficiency energy storage systems.

188Halloysite nanotubes, earth abundant alumosilicate tubular clay, are used to construct hierarchical composite with nickel sulfide (Ni3S2) via glucose-assisted hydrothermal reaction. The composite electrode shows high specific capacitance and cycling stability in supercapacitors. Results from this work provide insights into synthetic control of composition and morphology of hybrid composites and electrochemical properties of metal oxide/sulfide electrode.