Stabilizing Polymer–Lithium Interface in a Rechargeable Solid Battery

• DOI: 10.1002/adfm.201908047
• Publication Date: 2019-11-14T12:13:17Z
• Authors: Min Yan; Jia‐Yan Liang; Tong‐Tong Zuo; Ya‐Xia Yin; Sen Xin; Shuang‐Jie Tan; Yu‐Guo Guo; Li‐Jun Wan
• Keywords: 01 natural sciences; 7. Clean energy; 0104 chemical sciences

AbstractSolid polymer electrolytes (SPEs) are promising candidates for developing high‐energy‐density Li metal batteries due to their flexible processability. However, the low mechanical strength as well as the inferior interfacial regulation of ions between SPEs and Li metal anode limit the suppress ion of Li dendrites and destabilize the Li anode. To meet these challenges, interfacial engineering aiming to homogenize the distribution of Li+/electron accompanied with enhanced mechanical strength by Mg3N2 layer decorating polyethylene oxide is demonstrated. The intermediary Mg3N2 in situ transforms to a mixed ion/electron conducting interlayer consisting of a fast ionic conductor Li3N and a benign electronic conductor Mg metal, which can buffer the Li+ concentration gradient and level the nonuniform electric current distribution during cycling, as demonstrated by a COMSOL Multiphysics simulation. These characteristics endow the solid full cell with a dendrite‐free Li anode and enhanced cycling stability and kinetics. The innovative interface design will accelerate the commercial application of high‐energy‐density solid batteries.