Wei Qiulong

Nanowire device for electrochemical energy storage

Reducing capacity fading, increasing energy density and improving rate capability are the worldwide challenges in the development of electrochemical energy storage devices. Developing novel high-performance nanomaterials and devices is one of the effective solutions to overcome the challenges and explore the next-generation power batteries with high power density, high energy density and excellent cycling performance. Compared with bulk materials, nanowire electrode materials have more advantages in the assembly and in situ characterization of electrochemical devices for energy storage since unique anisotropy, fast axial electron transport and radial ion diffusion. Based on the new advance in this field and Mai groups work, we review that the single nanowire solid-state electrochemical device is designed and assembled, revealing the intrisinic principles of capacity fading with the decreasing of conductivity and deterioration of the structure through in situ characterization. Following the above discovery, chemical pre-intercalation and topotactical substitution as well as orderly oriented assembly are provided to improve the conductivity of the electrode materials, cycling stability and rate performance of the electrochemical devices by optimizing the intrinsic transport properties of the electrodes. In addition, hierarchical structure and one-dimensional buffer-effect hybrid structure are designed and constructed, which increase the specific surface area, active sites and minimized the structure degradation of nanowire during cycles, resulting in the enhancement of energy density, power density and lifespan. The above results lay a foundation for the development and applications of large-scale energy storage device and microdevices and even nanodevices.