Cell-like-carbon-micro-spheres for robust potassium anode

Large-scale low-cost synthesis methods for potassium ion battery (PIB) anodes with long cycle life and high capacity have 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 solid electrolyte interphase 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 mAhg(-1) at 100 mAg(-1) and 248mAhg(-1) at 500 mAg(-1)), excellent cycle stability (reversible capacity of 226 mAhg(-1) after 2100 cycles and a continuous running time of more than 15 months at a current density of 100 mAg(-1)), and an excellent rate performance (160mAhg(-1) at 1Ag(-1)). This study represents a new strategy for boosting battery performance, and could pave the way for the next generation of battery-powered applications.

Automated summary

Inspired by the structure of biological cells, biomimetic carbon cells (BCCs) were synthesized and used as anodes for potassium ion batteries (PIBs). The unique structural characteristics of BCCs result in PIBs with high capacity, excellent cycle stability, and outstanding rate performance.