High Li+ coordinated solvation sheaths enable high‐quality Li metal anode

Abstract

Abstract An advance Li‐sphere possessing a definitely regular morphology in Li deposition enables a well‐defined more robust structure and superior solid‐electrolyte interphase (SEI) to achieve high‐efficiency long‐term cycles in Li metal anode. Here, a new sight of high Li+ cluster‐like solvation sheaths coordinated in a localized high‐concentration NO3− (LH‐LiNO3) electrolyte fully clarifies for depositing advanced Li spheres. Moreover, we elucidate a critical amorphous‐crystalline phase transition in the nanostructure evolution of Li‐sphere deposits during the nucleation and growth. Li‐sphere anode exhibits ultra‐stable structural engineering for suppressing Li dendrite growths and rendering ultralong life of 4000 cycles in symmetrical cells at 2 mA cm−2. The as‐constructed Li spheres/3DCM|LiFePO4 (LFP) full cell delivers a high capacity retention of 90.5% at 1 C after 1000 cycles, and a robust dendrite‐free structure also stably exists in Li‐sphere anode. Combined with high‐loading LFP cathodes (6.6 and 10.9 mg cm−2), superb capacity retentions are up to 96.5% and 92.5% after 800 cycles at 1 C, respectively. Cluster‐like solvation sheaths with high Li+ coordination exert significant influence on depositing a high‐quality Li‐sphere anode.

Keywords

• advanced Li‐sphere deposition
• high‐quality cycling stability
• high Li+ coordinated solvation sheaths
• localized high concentration NO3‐
• ultra‐stable structural engineering