Dendrite-Free Non-Newtonian Semisolid Lithium Metal Anode

Abstract

Dendrite growth hinders the practical uses of the lithium metal anode (LMA) toward a high-energy-density battery. From the mechanics perspective, the lithium growth on a solid substrate yields a large strength, leading to a short circuit and worsened nonuniform lithium deposition. Inspired by quicksand in nature, we designed a non-Newtonian shear-thinning LMA. Such a quicksand-like LMA shows flowability under pressure and removes the solid substrate for dendrite growth, effectively releasing the stress in electrodes, especially at large current density and high deposition capacity. As a result, a good cycling performance is realized in symmetric cells even under a high current density of 20 mA cm^–2 and a high deposition capacity of 8 mAh cm^–2. The assembled Li–LiFePO₄ full cells also show a long stable cycling performance under a low N/P ratio. Moreover, the quicksand-like LMA eliminates the inner stress and keeps the integrity during repeated bending, showing potential use in flexible devices.