Trash to treasure: Carbon-free ZnSe derived from waste zinc foil as a high-rate and long-life anode material enabling fast-charging sodium-ion batteries

Abstract

A resource reuse strategy for recycling discarded zinc fragments from zinc-ion battery manufacturing is proposed to obtain carbon-free ZnSe anode material for sodium-ion batteries (SIBs), which are currently regarded as the solutions for future large-scale energy storage devices and distributed generation. Carbon-free ZnSe with micro-structure is conveniently prepared by calcining the discarded zinc fragment and selenium powder. ZnSe at optimal condition has an impressive initial Coulombic efficiency of up to 95.8% and a high capacity of 387.0 mAh g−1 at 0.1 A g−1. Providing a capacity of 142.5 mAh g−1 at 30 A g−1 shows the superb rate capability. Attractively, only 17.1 s is taken to complete a single charge, proving its application potential in fast-charging SIBs. Meanwhile, it also exhibits a conspicuous cyclability, corresponding to a capacity of 386.6 mAh g−1 at 2 A g−1 over 1600 cycles. Additionally, the full cell assembled Na3V2(PO4)2F3@reduced graphene oxide (rGO) cathode and ZnSe anode can light up 36 LEDs continuously with an ultimate energy density of 153.4 Wh Kg−1 and a maximum power density of 1108.5 W kg−1. This work aims to provide an available strategy for the synthesis of anode with high-rate performance and long cyclability for fast-charging SIBs.