Suppressing Dendrite Growth with Eco-Friendly Sodium Lignosulfonate Additive in Quasi-Solid-State Li Metal Battery.

The application of lithium metal batteries is limited by the drawbacks of safety problems and Li dendrite formation. Quasi-solid-state electrolytes (QSSEs) are the most promising alternatives to commercial liquid electrolytes due to their high safety and great compatibility with electrodes. However, Li dendrite formation and the slow Li diffusion in QSSEs severely hinder uniform Li deposition, thus leading to Li dendrite growth and short circuits. Herein, an eco-friendly and low-cost sodium lignosulfonate (LSS)-assisted PVDF-based QSSE is proposed to induce uniform Li deposition and inhibit Li dendrite growth. Li symmetric cells with 5%-LSS QSSE possess a high Li transfer number of 0.79, and they exhibit a long cycle life of 1000 h at a current density/areal capacity of 1 mA cm/5 mAh cm. Moreover, due to the fast electrochemical dynamics endowed by the improved compatibility of the electrodes and fast Li diffusion, the LFP/5%-LSS/Li full cells still maintain a high capacity of 110 mAh g after 250 cycles at 6C. This work provides a novel and promising choice that uses eco-friendly LSS as an additive to PVDF-based QSSE in Li metal batteries.