ZIF-8 derived porous carbon to mitigate shuttle effect for high performance aqueous zinc-iodine batteries.

Rechargeable aqueous zinc-iodine batteries (ZIBs) with low environmental impacts and abundant natural reserves have emerged as promising electrochemical energy storage devices. However, the shuttle effect and low conductivity of the iodine species cause poor electrochemical performance and hinder their practical application. Herein, we propose a ZIF-8 derived porous carbon (ZPC) for iodine species immobilization in ZIBs. The rich porous structure and highly conductive framework of ZPC provide efficient iodine loading and allow the fast transmission of electrons. In addition, the presence of N, Zn and ZnO in the carbon framework can build chemical anchoring with the iodine species to mitigate the shuttle effect. Thus, the ZPC/I2 cathode exhibits a reversible capacity of 156 mAh g-1 after 100 cycles at 100 mA g-1 and a long-term stability of 1000 cycles at a high rate. This study will open a new paradigm for devolving highly reversible ZIBs.