Enhanced faradic activity by construction of p-n junction within reduced graphene oxide@cobalt nickel sulfide@nickle cobalt layered double hydroxide composite electrode for charge storage in hybrid supercapacitor.

• A p-n junction composite was constructed to enhance the faradic activity. • Efficient interface electrons transfer across the junction was evidenced. • Substantially enhanced battery capacity was achieved. The intrinsic faradic reactivity is the uppermost factor determining the charge storage capability of battery material, the construction of p-n junction composing of different faradic components is a rational tactics to enhance the faradic activity. Herein, a reduced graphene oxide@cobalt nickle sulfide@nickle cobalt layered double hydroxide composite (rGO@CoNi 2 S 4 @NiCo LDH) with p-n junction structure is designed by deposition of n -type nickle cobalt layered double hydroxide (NiCo LDH) around p-type reduced graphene oxide@cobalt nickle sulfide (rGO@CoNi 2 S 4), the charge redistribution across the p-n junction enables enhanced faradic activities of both components and further the overall charge storage capacity of the resultant rGO@CoNi 2 S 4 @NiCo LDH battery electrode. As expected, the rGO@CoNi 2 S 4 @NiCo LDH electrode can deliver high specific capacity (C s , 1310 ± 26 C g−1 at 1 A g−1) and good cycleability (77% C s maintaining ratio undergoes 5000 charge-discharge cycles). Furthermore, the hybrid supercapacitor (HSC) based on the rGO@CoNi 2 S 4 @NiCo LDH p-n junction battery electrode exports high energy density (E cell , 57.4 Wh kg−1 at 323 W kg−1) and good durability, showing the prospect of faradic p-n junction composite in battery typed energy storage. [ABSTRACT FROM AUTHOR]