Surface graphited carbon scaffold enables simple and scalable fabrication of 3D composite lithium metal anode†
Abstract
Lithium metal is the most promising anode material due to its high specific capacity (∼3860 mA h g−1) and low electrochemical potential (−3.04 V vs. standard hydrogen electrode). However, lithium dendrite growth, low coulombic efficiency (CE) and the infinite relative volume change during lithium plating/striping cycles have severely limited its practical applications. Using a composite lithium metal anode fabricated by melt infusion of lithium is employed as an effective method to solve the aforementioned issues, but the fabrication process is always complicated and it is difficult to realize large-scale production. Herein, we demonstrate a simple and scalable method to fabricate a composite Li structure. By heat treatment at 1200 °C, a common carbon matrix turns into a surface graphited carbon scaffold, which possesses good Li affinity and can be used to fabricate a three-dimensional (3D) composite Li anode by Li melt infusion. The one-step method makes it easy to realize scalable and cheap production of a lithium affinity scaffold. We achieved stable cycling of the lithium metal anode for 100 cycles at a high current density of 3 mA cm−2 in a carbonate electrolyte. The full-cell batteries with the 3D composite Li anode also delivered better rate and cycling performance than those with a bare Li anode.