Pressure-tailored lithium deposition and dissolution in lithium metal batteries

TL;DR

This paper demonstrates that applying uniaxial stack pressure during operation enables the formation of dense, ideal lithium deposits with a columnar structure, improving safety and efficiency in lithium metal batteries.

Contribution

The study introduces a pressure-controlled method to achieve dense, reversible lithium deposits, advancing the design of safer and more efficient lithium metal batteries.

Findings

Achieved 99.49% electrode density with columnar Li deposits

Elucidated the role of stack pressure on Li nucleation, growth, and dissolution

Developed strategies to maintain ideal Li morphology during cycling

Abstract

A porous electrode resulting from unregulated Li growth is the major cause of the low Coulombic efficiency and potential safety hazards of rechargeable Li metal batteries. Strategies aiming to achieve large granular Li deposits have been extensively explored; yet, the ideal Li deposits, which consist of large Li particles that are seamlessly packed on the electrode and can be reversibly deposited and stripped, have never been achieved. Here, by controlling the uniaxial stack pressure during battery operation, a dense Li deposition (99.49% electrode density) with an ideal columnar structure has been achieved. Using multi-scale characterization and simulation, we elucidated the critical role of stack pressure on Li nucleation, growth and dissolution processes, and developed innovative strategies to maintain the ideal Li morphology during extended cycling. The precision manipulation of Li deposition and dissolution is a critical step to enable fast charging and low temperature operation for Li metal batteries.