Petaloid CuS nanocrystalline combined with nitrogen self-doped porous carbon as hybrid electrodes for supercapacitors

Copper sulfide (CuS) is a one of the ideal electrode materials for supercapacitors (SCs) due to the abundant raw materials, easy preparation and low cost. However, low conductivity and poor stability of the CuS electrodes plague their practical applications. Aiming at performances improvement of CuS based electrodes, a strategy to stimulate synergistic effect between CuS and carbon was developed. Composites containing activated nitrogen self-doped porous carbon (ANPC) and petaloid CuS nanocrystalline were prepared and studied as electrodes for SCs. The ANPC@CuS hybrid electrode achieved a maximum specific capacity of 1112.92 F g- 1 at 1 A g- 1 which is 3.5 times that of CuS electrode. Meanwhile, 97.97 % capacity retention after 10,000 cycles at 10 A g- 1 was gained. Asymmetric hybrid supercapacitor (HSC) with the ANPC@CuS electrode exhibited a maximum energy density of 29.84 Wh kg- 1 at 491.19 W kg- 1, and great cycling stability with 91.62 % capacity retention after 5000 constant current charge-discharge cycles at 10 A g- 1. This work provides an effective approach to stimulate synergistic effect of hybrid electrodes for high-performance SCs.