Silicon (Si), owing to its extremely high theoretical capacity (3579 mAh/g), is regarded as one of the most attractive anode materials for next generation lithium batteries. However, practical application of Si anode is severely hampered by its large volume expansion/shrinkage during lithiation/delithiation (discharging/charging). This expansion/shrinkage may give rise to anode particle pulverization, breaking the electrical contact between particles, and resulting in rapid capacity attenuation and limited cycle life. For better development of Si anode, it is essential to understand the underlying mechanism of the lithiation/delithiation process and the corresponding microstructure evolution. However, the lithiation/delithiation of Si anode involves complex transitions between the crystalline and amorphous phases, making any comprehensive analysis a challenging task. In addition, the stress state of an anode particle depends strongly on the lithiation/delithiation mechanism. For example, McDowell et al. pointed out that amorphous Si (a-Si) and crystalline Si (c-Si) have different stresses during lithiation. The stress distribution in a-Si particles is uniform and shows compressive hoop stress, which is beneficial to structural stability.