Polymer Zwitterion-Based Artificial Interphase Layers for Stable Lithium Metal Anodes
Tong Jin, Ming Liu, Kai Su, Yue Lu, Guang Cheng, Yao Liu, Nianwu Li, Le Yu
Abstract
Lithium (Li) metal batteries are promising future rechargeable batteries with high-energy density as the Li metal anode (LMA) possesses a high specific capacity and the lowest potential. However, the commercial application of the LMA has been hindered by a low Coulombic efficiency and dendrite growth, which are related to the unstable interphase with poor Li+ ion transport. Herein, we report novel polymer zwitterion-based artificial interphase layers (AILs) with improved Li+ ion transport and high stability for long-life LMAs. Benefitting from the unique zwitterion effect within the polymer zwitterion-based AILs, a high Li+ ion transference number (0.81) and a good ionic conductivity (0.75 × 10–4 S cm–1) can be realized simultaneously at the interface. By regulating the weight ratio of the sulfonate group and the phosphate group in polymer zwitterion-based AILs, the modified LMA enables long-term Li plating/stripping for 1400 h at 1 mA cm–2 and stable cycling in a full cell. This interfacial engineering concept could shed light on the development of safe LMAs.