An Aqueous Zn-Ion Hybrid Supercapacitor with High Energy Density and Ultrastability up to 80 000 Cycles

A novel cable-type flexible supercapacitor with excellent performance is fabricated using 3D polypyrrole(PPy)-MnO2 -CNT-cotton thread multi-grade nanostructure-based electrodes. The multiple supercapacitors with a high areal capacitance 1.49 F cm(-2) at a scan rate of 1 mV s(-1) connected in series and in parallel can successfully drive a LED segment display. Such an excellent performance is attributed to the cumulative effect of conducting single-walled carbon nanotubes on cotton thread, active mesoporous flower-like MnO2 nanoplates, and PPy conductive wrapping layer improving the conductivity, and acting as pseudocapacitance material simultaneously.

Cable-type supercapacitors of three-dimensional cotton thread based multi-grade nanostructures for wearable energy storage

Recent Developments and Future Prospects for Zinc‐Ion Hybrid Capacitors: a Review

Understanding the Design Principles of Advanced Aqueous Zinc‐Ion Battery Cathodes: From Transport Kinetics to Structural Engineering, and Future Perspectives

A Highly Flexible and Lightweight MnO2/Graphene Membrane for Superior Zinc‐Ion Batteries

Restricted by their energy storage mechanism, current energy storage devices have certain drawbacks, such as low power density for batteries and low energy density for supercapacitors. Fortunately, the nearest ion capacitors, such as lithium-ion and sodium-ion capacitors containing battery-type and capacitor-type electrodes, may allow achieving both high energy and power densities. For the inspiration, a new zinc-ion capacitor (ZIC) has been designed and realized by assembling the free-standing manganese dioxide–carbon nanotubes (MnO2–CNTs) battery-type cathode and MXene (Ti3C2Tx) capacitor-type anode in an aqueous electrolyte. The ZIC can avoid the insecurity issues that frequently occurred in lithium-ion and sodium-ion capacitors in organic electrolytes. As expected, the ZIC in an aqueous liquid electrolyte exhibits excellent electrochemical performance (based on the total weight of cathode and anode), such as a high specific capacitance of 115.1 F g−1 (1 mV s−1), high energy density of 98.6 Wh kg−1 (77.5 W kg−1), high power density of 2480.6 W kg−1 (29.7 Wh kg−1), and high capacitance retention of ~ 83.6% of its initial capacitance (15,000 cycles). Even in an aqueous gel electrolyte, the ZIC also exhibits excellent performance. This work provides an essential strategy for designing next-generation high-performance energy storage devices.

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Yanan Ma

Papers

A New Free-Standing Aqueous Zinc-Ion Capacitor Based on MnO 2 –CNTs Cathode and MXene Anode