We note that the expected standard potential of reaction (4) is 1 V higher than that of reaction (1), which we observe near ~1.3 V, and it is also typically found at ~2.3 V . Following the discussion and criteria above, it becomes apparent that H2 is the only common denominator between the HF-based and the water-based process, where the RRDE results additionally show that hydrogen is continuously generated during growth. Taken together, this leads us to believe that H2, rather than LiF, is the critical component for columnar lithium growth, which is the main result of this paper.