A novel hybrid electrode composited Ni-Sn alloys with SnOx for supercapacitors

Hybrid electrodes consisting of battery-type and capacitive-type materials show excellent electrochemical performance, which have attracted much attention for high-performance supercapacitors recently. This work proposes a novel strategy to fabricate Ni-Sn alloys enhanced hybrid electrodes by an ingenious one-step thermal treatment process, and the obtained Ni@a-SnOx samples are composed of SnOx, Ni and Ni-Sn alloys (c-Ni3Sn, h-Ni3Sn). Thereinto, the existence of Ni-Sn alloys would enhance the electrochemical performance of samples due to their high electrical conductivity as well as extra Faradaic redox reactions. During electrochemical measurements, the Ni@a-SnOx electrodes exhibit both capacitive-type and battery-type behaviors, and the maximum specific capacitance achieves 29.6 mAh·g−1 (or 177.6 F·g−1) at a current density of 1 A·g−1, which shows outstanding rate capability. Besides, capacitance retention of the optimal Ni@a-SnOx sample increases first and then decreases slightly during 1000 charge-discharge cycles, reaching 2.7 times higher than the original value after 600 cycles, implying superior electrochemical performance. Furthermore, the facile method could be extended to fabricate other kinds of alloy-enhanced metal oxide electrodes for new generation supercapacitors in the future.