Leveraging impurities in recycled lead anodes for sodium-ion batteries

In recent years, the supply chain shock due to the rapid rise of the lithium-ion battery has made alternative chemistries, such as sodium-ion batteries, appealing for low-cost and large-scale energy storage. Meanwhile, the falling popularity of lead acid batteries has potential consequences for the price of scrap lead and its penetration into waste streams. In this work, we upcycle lead alloys from a used lead acid battery into a next-generation sodium-ion system for ultra-low-cost rechargeable batteries. Through evaluation of sodium storage capacity and rate capability, we study the rich interplay of Pb-Sb-Sn microstructure and properties which can be controlled through simple heat treatment of unrefined powders to reach a maximum specific capacity of 522 mAh.g-1. When cycled in the presence of glyme-based electrolytes, the ternary alloys nanostructure to facilitate an optimal balance of power and cycle life. These findings that demonstrate how defects can be leveraged to improve performance bring exciting implications for reducing cost and mitigating volume expansion in other high-value commodities, like tin or silicon.