Rechargeable aqueous zinc-ion batteries (ZIBs) have gained particular attention in recent years because of their low cost and high safety. However, most of their performances are limited by unsatisfied architecture of cathodes. In addition, the degree of crystallinity of active materials also plays an important role in their electrochemical performance. Herein, we fabricated free-standing composite films with amorphous MnO₂ (a-MnO₂) and carbon nanotubes (CNTs) by an in situ deposition method. The free-standing a-MnO₂@CNTs composite films can directly serve as the cathodes of ZIBs without binder and current collector. The resultant cathode exhibits highly electrical conductivity and fast ion-diffusion because of the corporation of interconnected three-dimensional CNTs architectures and ultra-thin a-MnO₂ nanosheets. As a result, the resultant ZIB displays high energy and power density, as well as stable cycling performance. Moreover, based on composite films, flexible ZIBs were constructed, and they could remain stable electrochemical performance under different bending states, which have great potential for the application in flexible and wearable electronics.

近年来，由于其低成本和高安全性，可再充电的水性锌离子电池（ZIB）受到了特别的关注。然而，它们的大多数性能受到不满意的阴极结构的限制。另外，活性材料的结晶度在它们的电化学性能中也起重要作用。在这里，我们通过原位沉积法制备了具有非晶态MnO ₂（a-MnO ₂）和碳纳米管（CNT）的自支撑复合膜。独立的a-MnO ₂@CNTs复合膜可以直接用作ZIBs的阴极，而无需粘合剂和集电器。由于互连的三维CNT结构和超薄的a-MnO ₂纳米片的结合，所得阴极显示出高电导率和快速的离子扩散。结果，所得的ZIB显示出高能量和功率密度，以及稳定的循环性能。此外，基于复合膜，构建了柔性ZIBs，它们可以在不同的弯曲状态下保持稳定的电化学性能，在柔性和可穿戴电子产品中具有广阔的应用前景。