Water-in-Polymer Salt Electrolyte for Dendrite-Free Zn- Lignin Battery

Abstract

Zn-ion batteries are considered to be a promising option for low-cost and sustainable secondary batteries. However, one of the current challenges facing this technology is hydrogen evolution and dendritic growth during Zn deposition. To address these issues, a new strategy is to use "water-in-salt" electrolyte (WISE), which refers to super concentrated aqueous electrolytes. This helps to broaden the electrochemical stability window (ESW), suppress the hydrogen evolution reaction (HER), and impede dendritic growth. In this paper, we propose the idea of using "water-in-polymer salt" electrolyte (WIPSE) to address the challenges facing Zn-ion batteries and move this technology towards becoming one of the most affordable, environmentally friendly, and sustainable options. Specifically, we suggest using a lignin-carbon electrode, which is highly promising and has great potential for achieving these goals. The findings suggest reversible Zn deposition and dissolution, leading to dendrite free Zn deposition. The sustainable Zn-lignin battery exhibited remarkable performance, with a maximum energy of 23 Wh/Kg and a maximum power of 610 W/kg, low self-discharge and 82% retention in capacity after 8000 cycles. Given its improved environmental impact and cost-effectiveness, the Zn-lignin battery holds a promising position in the battery market.