Coupling Dead-Lithium Reactivation and Interfacial Stabilization for Long-Life Lithium Metal Batteries.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium metal batteries (LMBs) suffer from poor cycling stability due to anode interfacial issues and dead lithium formation.
• Instability arises from lithium metal anode reactions and inactive lithium accumulation, limiting battery life.

Purpose of the Study:

• To develop a multifunctional artificial anode interphase for stabilizing lithium metal anodes in LMBs.
• To address lithium inventory loss and improve cycling stability through in situ formation of a composite interphase.

Main Methods:

• A one-step interfacial reaction between bismuth(III) iodide (BiI3) and lithium metal was used to form an in situ composite interphase of lithium bismuthate (Li3Bi) and lithium iodide (LiI).
• The electrochemical performance of the modified lithium anode was evaluated, including cycling stability, rate capability, and interfacial properties.
• The mechanism of lithium deposition, ion transport, and dead lithium reactivation was investigated.

Main Results:

• The Li3Bi/LiI interphase enhanced interfacial coupling, mechanical strength, and Li+ transport, extending Sand's time and promoting uniform lithium deposition.
• A reversible iodide/triiodide redox process within the LiI component enabled continuous reactivation of dead lithium into cyclable Li+.
• The optimized anode demonstrated ultra-long, dendrite-free cycling exceeding 10,000 hours and stable operation over 450 hours at 10 mA cm-2.
• LMBs with the protected anode and a LiFePO4 cathode retained 94.4% capacity after 500 cycles.

Conclusions:

• The integrated approach of interfacial stabilization and active lithium recycling in a single protective layer offers a viable strategy for developing long-life LMBs.
• The multifunctional Li3Bi/LiI interphase effectively mitigates key challenges in lithium metal anode performance.
• This work presents a promising solution for advancing the practical application of high-energy-density lithium metal batteries.