Hybrid Energy Storage of Ni(OH)-coated N-doped Graphene Aerogel//N-doped Graphene Aerogel for the Replacement of NiCd and NiMH Batteries.

Although Nickel-Cadmium (NiCd) and Nickel-metal hydride (NiMH) batteries have been widely used, their drawbacks including toxic Cd and expensive La alloy at the negative electrodes, low energy density (40-60 Wh/kg for NiCd and 140-300 Wh/L for NiMH), low power density (150 W/kg for NiCd and 1000 W/kg for NiMH), and low working potential (1.2 V) limit their applications. In this work, Cd and La alloy were replaced with N-doped reduced graphene oxide aerogel (N-rGO) providing a hybrid energy storage (HES) having the battery and supercapacitor effects.

High-Performance Asymmetric Supercapacitors of MnCoO Nanofibers and N-Doped Reduced Graphene Oxide Aerogel.

The working potential of symmetric supercapacitors is not so wide because one type of material used for the supercapacitor electrodes prefers either positive or negative charge to both charges. To address this problem, a novel asymmetrical supercapacitor (ASC) of battery-type MnCoO nanofibers (NFs)//N-doped reduced graphene oxide aerogel (N-rGO) was fabricated in this work. The MnCoO NFs at the positive electrode store the negative charges, i.