Mesoporous Co@N-rich carbon hybrids for a high rate aqueous alkaline battery

Abstract

Metal cobalt has infinite potential for super performance aqueous alkaline batteries. But it is a high degree of requirements to design and synthesize composites to solve the common problems than Co materials. Hence towards that end, Co@N-rich carbon hybrids (CoNC) have been designed and prepared via an in-situ, facile and effective method. By doping abundant nitrogen (about 5wt%), the mesoporous carbon shells provide more active sites, enhanced electrical conductivity and electrode infiltration, and avoid the Co nanoparticles agglomeration and serious electrode dissolution. When used as the electrode for the aqueous alkaline battery, the CoNC hybrids deliver outstandingly higher discharge capacity, superior high-rate ability, and stable cycling ability. A high discharge capacity of 625mAhg−1 has been delivered at 500mAg−1 and reduced to 455.7mAhg−1 after 150 cycles for the CoNC electrode. Even the current increases up to 5Ag−1, the capacity still remains at 461.3mAhg−1, manifesting the fascinating high-rate discharge ability. Importing the rich nitrogen species makes a significant difference to give full play a positive role on the aqueous alkaline battery, which as well guides a new direction towards high-rate power batteries.