3D oxidized polyacrylonitrile/Ag framework guided bottom-up lithium deposition for dendrite-free lithium metal batteries

Abstract

Lithium (Li) metal anode is considered as the “Holy Grail” for next-generation ultrahigh-energy-density lithium-ion batteries, but its application is tremendously limited by the demerits of uncontrolled dendrite growth, unrestricted volume expansion, and continuous side reactions. Herein, a 3D oxidized polyacrylonitrile (PAN)/Ag framework is designed to realize a bottom-up Li deposition and dendrite-free growth. The electronic insulator nature of the oxidized PAN guides a bottom-up lithium deposition to largely prevent volume expansion. In addition, the Ag nanoparticles on the PAN surface directly form a Li-Ag alloy with as-deposited Li, resulting in a low nucleation barrier. Furthermore, Li-Ag, as a Li+ conductor, induces a uniform and dense Li deposition. As a result, the oxidized PAN/Ag framework offers a long lifespan over 1200 h at a current density of 0.5 mA cm−2 and an areal capacity of 1 mAh cm−2. Moreover, in a full cell coupled with LiNi0.9Co0.1O2 cathode, a capacity retention of 84% after 100 cycles is achieved. This study provides a guideline to fabricate stable Li metal anode and highlights the key role of controlling electronic and ionic transportation separately in the 3D framework.