Nickel–cobalt layered double hydroxide nanosheets supported on carbon fibers derived from hydrogen production byproducts for high-performance water-based rechargeable nickel–zinc batteries

Nickel–zinc (NiZn) batteries offer promise for high-power aqueous energy storage but remain limited by the poor conductivity and structural instability of nickel-based cathodes. In this work, we introduce a cost-effective fibrous carbon material, derived as a byproduct of the hydrogen reforming process, as a novel conductive support to enhance the performance of NiCo layered double hydroxide (NiCo-LDH) cathodes. A NiCo-LDH/carbon composite (NiCo-LDH/CBP) was synthesized through a simple probe sonication method that enables uniform growth and strong integration of NiCo-LDH nanosheets within the fibrous carbon framework. Structural and spectroscopic analyses confirm the successful formation of the composite architecture. The resulting NiCo-LDH/CBP composite delivers a high capacity of 189 mAh g−1 at 1 A g−1, strong rate capability, and 81% retention over 900 cycles. A full NiZn cell achieves 206 mAh g−1 and an energy density of 349 Wh/kg. Density functional theory calculations further reveal that NiCo-LDH/C exhibits an improved electronic structure and enhanced charge-storage capability compared with pristine NiCo-LDH, confirming the beneficial role of carbon incorporation in the LDH framework. This work provides a sustainable strategy for converting industrial carbon waste into high-performance cathode materials for advanced NiZn batteries.