High-Performance Cable-Type Flexible Rechargeable Zn Battery Based on MnO₂@CNT Fiber Microelectrode

Abstract

Nowadays, linear-shaped batteries have received increasing attentions because the unique one-dimensional architecture offers an omni-directional flexibility. We developed a cable-type flexible rechargeable Zn microbattery based on a microscale MnO₂@carbon nanotube fiberlike composite cathode and Zn wire anode. The Zn-MnO₂ cable microbattery exhibits a large specific capacity, good rate performance, and cyclic stability. The capacity of Zn-MnO₂ cable batteries are 322 and 290 mAh/g based on MnO₂ with aqueous and gel polymer electrolyte, corresponding to the specific energy of 437 and 360 Wh/kg, respectively. Besides, the Zn-MnO₂ cable battery shows excellent flexibility, which can be folded into arbitrary shapes without sacrificing electrochemical performance. Furthermore, we studied electrochemical properties of Zn-MnO₂ cable microbatteries with different Zn salt electrolytes, such as Zn salt with small anions (ZnSO₄ or ZnCl₂, etc.) and Zn salt with bulky anions (Zn(CF₃SO₃)₂, etc.). With the merits of impressive electrochemical performance and flexibility, this first flexible rechargeable Zn-MnO₂ cable-like battery presents a new approach to develop high-performance power sources for portable and wearable electronics.