The densifying kinetics of lithium dendrites is characterized with effective activation energy of Ea ≈ 6 - 7 kcal mol(-1) in our experiments and molecular dynamics computations. We show that heating lithium dendrites for 55 °C reduces the representative dendrites length λ¯(T,t) up to 36%. NVT reactive force field simulations on three-dimensional glass phase dendrites produced by our coarse grained Monte Carlo method reveal that for any given initial dendrite morphology, there is a unique stable atomic arrangement for a certain range of temperature, combined with rapid morphological transition (∼10 ps) within quasi-stable states involving concurrent bulk and surface diffusions. Our results are useful for predicting the inherent structural characteristics of lithium dendrites such as dominant coordination number.