Simple electrodeposition of 3D NiCoFe-layered double hydroxide nanosheet assembled nanospheres/nanoflowers on carbon cloth for high performance hybrid supercapacitors

Abstract

Although layered double hydroxides (LDHs), especially NiCo-based LDHs, have been verified to be a type of potential cathode material for supercapacitors with high specific capacity and electric conductivity, their lifespan and rate performance are still not satisfactory. Herein, a series of 3D NiCoFe-LDH samples with different molar ratio of Ni/Co/Fe are successfully fabricated on carbon cloth via an electrodeposition method. It is found that NiCoFe-LDH nanosheet assembled nanospheres/nanoflowers electrode delivers high specific capacity, electrical conductivity, and more importantly, more superior rate performance as well as cycle stability than pristine NiCo-LDH electrode without Fe introduction. Moreover, the as-assembled hybrid supercapacitor device with NiCoFe-LDH and activated carbon as the cathode and anode respectively displays a wide voltage window (0–1.5 V), large specific energy (65 W h kg⁻¹ at the specific power of 83 W kg⁻¹) together with an ultrahigh cycle stability (26% capacity increment after 5000 cycles). With the merits of ease to fabricate and outstanding energy storage property, the newly assembled hybrid supercapacitor delivers great potential for practical application in the near future.