1. Introduction
With fast advancements in wearable and portable electronics, the urgent
need for a comprehensive array of energy storage solutions with high
surface energy and power densities, quick charging-discharging, and
stable cycle performance has been raised and is being widely
explored.1-5
The primary obstacle hampering the practical utilization of zinc ion
hybrid supercapacitors (ZISCs) is the scarcity of cathode materials with
high reversible capacitance, reliable cycling stability, and suitable
operating voltage. Transition metal oxides exhibit excellent
electrochemical properties in aqueous solution, including fast discharge
kinetics and high multiplicity performance.6-10MnO2 has become a particularly attractive option for
ZISCs cathode materials due to its reasonable price, ease of processing,
and eco-friendliness.11 Due to the tunneling and
layered structure, MnO2 can offer ample pathways and
active sites for the transport and embedding of various ions, such as
Li, Na, K, and Zn ions.12 Xu et al. assembled the
ZISCs with the MnO2 nanorods anode, AC cathode, and
ZnSO4 (2M) electrolyte, and different mass ratios of
electrodes were investigated.13 At the most suitable
mass ratio of 2.5:1, the ZISCs could operate with an operating range of
0-2.0 V. The structure and conductivity of MnO2-based
ZISCs need to be improved to gain a commercial market position. Chen et
al. studied the pre-intercalation of Zn2+ on the
carbon cloth with a substantial loading quantity of 12 mg
cm-2 to grow highly stabilized
ZnxMnO2 nanowires with tunneling
structures, obtaining excellent electrochemical
properties.14 However, the lack of
MnO2 conductivity still affects the cycling stability of
ZISCs.15,16
In the present work, a new type of ZISCs is assembled using Mn-based
cathode and carbon-based anode materials. ZnxMnO2 (ZMO)
nanowires were fabricated by the ordinary hydrothermal method, and
investigated the microscopic morphology structure and electrochemical
performance of ZMO/PPy (ZMOP). The addition of
Zn(NO3)2 provides a
Zn2+ ion, which makes the structure of
MnO2 more stable than before. The unique structure of
PPy can greatly improve the electrical conductivity and cycle efficiency
of Mn-based electrodes. When ZMOP was used as the cathode material of
ZISCs, the PPy-derived porous carbon nanotubes (PCNTs) were selected as
the anode material to assemble ZMOP//PCNT ZISCs. The
insertion-extraction on the positive electrode of ZMOP nanowires and the
adsorption-desorption on the PCNTs negative electrode shows excellent
electrochemical properties. The assembled ZISCs delivered an outstanding
energy density of 37 wh kg-1 with a power density of
64 w kg-1, it could maintain a capacity of 86.4% for
5000 cycles at 0.2 Ag-1.