Is All Lithium Created Equal? Effects of Processing Conditions on Lithium Microstructure and Battery Performance

Area of Science:

• Materials Science
• Electrochemistry
• Battery Technology

Background:

• Rechargeable lithium metal batteries are of high interest.
• Anode microstructure's impact on battery performance is often overlooked.
• Lithium's properties complicate standard characterization methods (SEM, EBSD).

Purpose of the Study:

• To investigate the influence of anode microstructure on lithium metal battery performance.
• To characterize morphology and microstructure of lithium films.
• To correlate microstructure with electrochemical performance.

Main Methods:

• Utilized scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), and X-ray diffraction (XRD).
• Assessed thermally evaporated and commercial lithium films.
• Conducted electrochemical measurements for lithium electroplating/stripping.

Main Results:

• Evaporated lithium's texture weakly depends on substrate; grain size/structure depend on film thickness.
• Commercial lithium films show significant microstructural variations.
• Thicker, coarse-grained lithium films enhanced cycling stability under low stack pressure (<1 MPa).
• Interfacial contact loss was the primary failure mode.

Conclusions:

• Anode microstructure significantly impacts lithium electroplating/stripping.
• Controlling anode microstructure is essential for next-generation lithium metal batteries.
• Further research needed to establish direct microstructure-performance correlations for commercial lithium sources.