Abstract
Large-scale low cost synthesis methods for potassium ion battery (PIB) anodes with long cycle life and high capacity has remained challenging. Here, inspired by the structure of a biological cell, biomimetic carbon cells (BCCs) were synthesized and used as PIB anodes. The protruding carbon nanotubes across the BCC wall mimicked the ion transporting channels present in the cell membrane, and enhanced the rate performance of PIBs. In addition, the robust carbon shell of the BCC could protect its overall structure, and the open space inside the BCC could accommodate the volume changes caused by K+ insertion, which greatly improved the stability of PIBs. For the first time, a stable SEI layer is formed on the surface of amorphous carbon. Collectively, the unique structural characteristics of the BCCs resulted in PIBs that showed a high reversible capacity (302 mAh g–1 at 100 mA g–1 and 248 mAh g–1 at 500 mA g–1), excellent cycle stability (reversible capacity of 226 mAh g–1 after 2100 cycles and a continuous running time of more than 15 months at a current density of 100 mA g–1), and an excellent rate performance (160 mAh g–1 at 1 A g–1). This study represents a new strategy for boosting the battery performance, and could pave the way for the next generation battery-powered applications.
Ni(OH)2@Ni core-shell nanochains as low-cost high-rate performance electrode for energy storage applications
