Hybrid Energy Storage of Ni(OH)2-coated N-doped Graphene Aerogel//N-doped Graphene Aerogel for the Replacement of NiCd and NiMH Batteries

Pichamon Sirisinudomkit,Peerapan Dittanet,Tanut Pettong,Pawin Iamprasertkun,Atiweena Krittayavathananon,Montree Sawangphruk

doi:10.1038/s41598-017-01191-8

Abstract

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-rGOae) providing a hybrid energy storage (HES) having the battery and supercapacitor effects. The HES of Ni(OH)2-coated N-rGOae//N-rGOae provides 1.5 V, a specific energy of 146 Wh/kg, a maximum specific power of 7705 W/kg, and high capacity retention over 84.6% after 5000 cycles. The mass change at the positive electrode during charging/discharging is 8.5 µg cm−2 owing to the insertion/desertion of solvated OH− into the α-Ni(OH)2-coated N-rGOae. At the negative electrode, the mass change of the solvated K+, physically adsorbed/desorbed to the N-rGOae, is 7.5 μg cm−2. In situ X-ray absorption spectroscopy (XAS) shows highly reversible redox reaction of α-Ni(OH)2. The as-fabricated device without using toxic Cd and expensive La alloy has a potential as a candidate of NiCd and NiMH.

Highlights

The Nickel–Cadmium (NiCd) and Nickel–metal hydride (NiMH) batteries have been widely used, their drawbacks including toxic cadmium and expensive lanthanum 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 electric vehicles, laptops, and mobile phones when compared with Li-ion batteries[1, 2]
nitrogen-doped reduced graphene oxide (N-rGOae) was coated on flexible carbon fiber paper (CFP) substrate for which the N-rGO sheets are interconnected each other forming high porosity aerogel
A transmission electron microscopy (TEM) image of N-rGOae in Fig. 1c indicates a few layers of N-rGOae sheets forming the wrinkle structure confirming the framework structure of the aerogel

Summary

Aerogel for the Replacement of NiCd and NiMH Batteries

Pichamon Sirisinudomkit[1,2], Pawin Iamprasertkun[1], Atiweena Krittayavathananon[1], Tanut Pettong[1], Peerapan Dittanet2 & Montree Sawangphruk[1]. 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. The Nickel–Cadmium (NiCd) and Nickel–metal hydride (NiMH) batteries have been widely used, their drawbacks including toxic cadmium and expensive lanthanum 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 electric vehicles, laptops, and mobile phones when compared with Li-ion batteries[1, 2]. The result shows that the AES of α-Ni(OH)2-coated N-rGOae//N-rGOae can store charges via both physical adsorption and redox reaction

Results and Discussion

Conclusions

Additional Information