Scalable solid solution strengthened Li–Ag alloy anodes for high-energy-density lithium batteries

Abstract

Lithium metal is considered a highly promising candidate for anodes in high-energy-density batteries. However, a key challenge lies in creating ultrathin anode foil (≤50 μm) with exceptional mechanical and electrochemical properties. In this study, a simple method is presented for producing an ultrathin strip of a Li-rich composite alloy anode (Li–Ag alloy) through mechanical rolling. The composite anode enhances diffusion kinetics, promotes uniform Li deposition, and effectively suppresses the growth of Li dendrites. Additionally, the composite anode's improved mechanical strength allows for the fabrication of foil as thin as 12 μm. The symmetric cell utilizing composite anodes demonstrates an impressive lifespan exceeding 900 hours at 1 mA cm⁻² and a high capacity of 4 mA h cm⁻². When paired with commercial LiNi_0.9Co_0.05Mn_0.05O₂ (NCM90) cathodes of high mass load, a full cell exhibits enhanced cycling performance with 97.8% capacity retention after 200 cycles. Particularly noteworthy is the successful development of a practical NCM90‖Li pouch cell, boasting a large capacity of 15.8 Ah and an energy density of 451.1 W h kg⁻¹.