Li+ attraction-repulsion synergy revealed by in-situ Raman spectroscopy for self-healing lithium metal anodes

Abstract

Lithium has attracted tremendous interest by its low reduction potential and high theoretical capacity when employed in metal batteries. However, intrinsic limitation of volume expansion and dendrites growth hinder their further development. In this work, we fundamentally revealed the Li+ platting pathways and put forward a Li+ attraction-repulsion synergy by in-situ Raman spectroscopy based on a scaffold (PEI@Ag@Cu). Lithiophilic Ag is prone to appeal Li+ and deposits as Li bulk, and electropositive polyethyleneimine (PEI) tends to absorb at protuberances and repulses Li+ enrichment, synergically resulting in dendrites free and volume expansion restrained deposition pattern. The average coulombic efficiency (CE) is high up to 99.1% at 3 mA cm−2 after 200 cycles in half-cell. The corresponding symmetric cell exhibits superior stable voltage profile accompanied by ultra-low voltage hysteresis for about 2500 h. This strategy provides a new inspiration for the preparation of hybrid lithium metal anodes from a special attraction-repulsion synergy.