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
