N-doped polyacrylonitrile carbon fiber interlayer for uniform and dendrite free Zn metal battery

The aqueous zinc-ion battery's (AZBs) inherent safety and inexpensive cost make it an attractive prospect for next-generation energy storage. Nevertheless, AZBs are presently troubled by the formation of Zn dendrites and unwanted side-reactions, which can lead to cycling instability and premature collapse. This study demonstrates the fabrication of an N-doped polyacrylonitrile (PAN) carbon fiber (PCF) network with ionic conductivity using the electrospinning of a PAN solution followed by thermal treatment. Zn plating and stripping behavior can be controlled by using a three-dimensional PCF with a polar functional group as an interlayer covering on the zinc anode. This allows for partially deposited zinc to be accommodated, which ultimately results in zinc dendrite-free deposition on the zinc anode. This phenomenon is initially proven in Zn@PCF symmetric cells, and then it is demonstrated further in Zn@PCF/MnO₂ whole cells, where the dendritic Zn anode surfaces become completely smooth and devoid of any features. This results in a charging and discharging cycle that is far longer than one would normally experience. The findings of this study offer a viable path toward the development of dendrite-free AZBs with great performance.