Manipulating nickel oxides in naturally-derived cellulose nanofiber networks as robust cathodes for high-performance Ni–Zn batteries
Nickel–zinc (Ni–Zn) batteries have been currently regarded as the promising energy storage devices for their high efficiency, high output voltage and good safety. However, the low energy density and poor rate performance caused from insufficient active sites and slow electron/ion transportation impede their future development in large-scale applications. To boost their electrochemical performance, we designed a new Ni-based composite with unique structure by anchoring Ni–NiO nanoparticles into a naturally-derived and networked cellulose nanofiber carbon (denoted as Ni–NiO/CC), which can work as robust cathodes for Ni–Zn batteries. Benefiting from the elaborate structure that can speed up charge transportation and increase active sites of cathode materials, the capacity of Ni–NiO/CC is remarkably boosted from 2.3 mAh/g to 184 mAh/g at 0.625 A/g. The as-fabricated Ni–NiO/CC//Zn battery delivers high capacity (256 mAh/g at 0.625 A/g), superior rate performance (68.5% capacity retention at 25 A/g), as well as good cycling durability (87.5% retention after 2000 cycles). More importantly, the maximum power density for Ni–NiO/CC//Zn battery is 41.6 kW/kg, posing a peak energy density of 441.7 Wh/kg. This work ignites the spark that facile manipulating nanostructured electrodes based on sustainable biomass for green and advanced aqueous rechargeable batteries.