Highly flexible and compressible zinc-ion batteries with superb electrochemical performance enabled by a dual structural regulation strategy

Abstract

Aqueous zinc-ion batteries (ZIBs) have attracted considerable research attention recently owing to their superior features. However, various critical issues, such as insufficient energy density, poor rate capability, short cycle life, and overlooked mechanical stability, seriously impede their practical application. Although numerous efforts have been devoted to ZIBs improvement, their performance boost is usually unsatisfactory and one-sided. Herein, a simple and versatile strategy is proposed to simultaneously address these issues through synergistic dual structural regulation of the electrodes. The structural orientation regulation of electrode not only facilitate electrolyte diffusion and ion transfer, but also make the electric field distribution and Zn2+ ion flux more uniform. Consequently, the resulting ZIBs exhibit great rate capability and stunning cycling stability (around 0.0003% of attenuation per cycle). On this basis, the further structural size regulation of electrode endues the ZIBs with both ultrahigh MnO2 loading (202.53 mg cm−3) and remarkable volumetric energy density (43.11 mWh cm−3), outperforming most of the state-of-the-art batteries of this kind. Additionally, the tenacious electrodes endow the fabricated ZIBs with coveted flexibility, compressibility, and extremely high safety, well suited to the needs of wearable electronics. This work provides a much more facile and promising way for the design of advanced ZIBs with excellent electrochemical performance and unparalleled mechanical toughness.