Vertical Graphene Film Enables High-Performance Quasi-Solid-State Planar Zinc-Ion Microbatteries
Yumei Zhou, Wangyang Li, Yonghui Xie, Liying Deng, Bingyuan Ke, Yijia Jian, Shuying Cheng, Baihua Qu, Xinghui Wang
Abstract
With the advantages of low cost, high safety, and environmental friendliness, quasi-solid-state zinc-ion microbatteries (ZIMBs) have received widespread attention in the field of flexible wearable devices and on-chip integratable energy storage. However, hysteresis Zn-ion transport kinetics and inhomogeneous growth of the zinc anode result in the poor capacity reversibility and cycling stability. Herein, a quasi-solid-state planar zinc-ion cell was developed by employing a vertical graphene (VG) film as an effective conductive modification layer for both the cathode and anode. The VG distinctly induces uniform Zn deposition/stripping, accelerates the charge transport, and enhances the adhesion between the active materials and current collectors. As a result, planar Zn@VG//MnO 2 @VG exhibits a high areal capacity of 159 μAh cm –2, a remarkably high areal energy/power density of 201.5 μWh cm –2 /67.16 μW cm –2, and a high capacity retention of 95.6% at a bending angle of 180°. The proposed facile strategy for electrode modification provides a new insight into the design of high-performance flexible and planar ZIMBs.