Researchers from Sogang University and Hyundai have quantitatively revealed the effect of surface topography of lithium metal anodes on dendrite growth using an electro-chemo-mechanical phase-field model. A paper on their work is published in the Journal of Power Sources.

Lithium (Li) metal, which has the advantages of high theoretical capacity, low redox potential, and low density, is considered an ideal anode material for next-generation battery systems. However, the dendritic morphology of Li-metal electrodeposition during the charging process remains challenging because it results in active Li depletion, poor cycling performance, and safety issues.

—Lee et al.

The team measured and quantified the surface topography of the Li-metal battery using the arithmetic mean roughness (Ra), root mean square roughness (Rq), impulse factor (Rp), skewness, and kurtosis.

The simulation results showed that the arithmetic mean height of the bare electrode and the height of the highest tip compared to the average height were highly correlated with dendrite growth.

They also showed controlling the surface topography, applied voltage, and external pressure can effectively suppress dendritic growth. Furthermore, the exposed surface of the electrode generated by the size difference or misalignment of the electrodes induced considerable dendrite growth.

Resources

• Hyunjoo Lee, Taejin Kwak, Wooju Lee, Jongchan Song, Dongchoul Kim (2022) “Effect of surface topography on dendritic growth in lithium metal batteries,” Journal of Power Sources, Volume 552 doi: 10.1016/j.jpowsour.2022.232264