Tellurium-tin based electrodes enabling liquid metal batteries for high specific energy storage applications

Developing high energy density batteries is of great significance for various energy storage applications . The novel liquid metal batteries (LMBs), with the merits of low-cost and long-lifespan, however deliver relatively low specific energy due to the electromotive force (EMF) limitation of bimetallic electrodes. Metalloid tellurium (Te) is a potentially high voltage electrode candidate for LMB, but challenged by its poor electronic conductivity and high solubility in molten salts. Herein, for the first time, we demonstrate a high voltage LMB with high energy density enabled by metalloid Te alloying with metallic Sn as positive electrode . This Te-Sn alloying strategy dramatically enhances the electronic conductivity of Te based electrodes, and suppresses the solubility of Te in molten salt electrolyte as well. The Li||Te-Sn cells reported herein present the highest discharge voltage of ca.1.6 V and energy density of 495 Wh kg −1 among all the reported LMBs. These preliminary results broaden the selection of positive electrode materials for LMBs and demonstrate a strategy for developing high energy density batteries for energy storage applications.