ZnxMnO2/PPy nanowires composite as cathode material for aqueous Zinc-ion
hybrid supercapacitors
Abstract
Over the past decade, the extensive consumption of finite energy
resources has caused severe environmental pollution. Meanwhile, the
promotion of renewable energy sources is limited by their intermittent
and regional nature. Thus, developing effective energy storage and
conversion technologies and devices holds considerable importance.
Zinc-ion hybrid supercapacitors (ZISCs) merge the beneficial aspects of
both supercapacitors and batteries, rendering them an exceptionally
promising energy storage method. As an important cathode material for
ZISCs, the tunnel structure MnO 2 has poor conductivity
and structural stability. Herein, the Zn xMnO
2/PPy (ZMOP) electrode materials are prepared by
hydrothermal method. Doping with Zn 2+ is used to
enhance its structural stability, while adding polypyrrole to improve
its conductivity. Therefore, the fabricated ZMOP cathode presents superb
specific capacity (0.1 A g -1, 156.4 mAh g
-1) and remarkable cycle performance (82.6%, 5000
cycles, 0.2 A g -1). Furthermore, the assembled
aqueous ZISCs with ZMOP cathode and PPy-derived porous carbon nanotubes
anode obtain a superb capacity of 109 F g -1 at 0.1 A
g -1. Meanwhile, at a power density of 867 W kg
-1, the corresponding energy density can achieve 20 Wh
kg -1. And over 5000 cycles at 0.2 A g
-1, the ZISCs can exhibit excellent cycle stability
(86.4%). This suggests that ZMOP nanowires are potential cathode
materials for superior-performance aqueous ZISCs.