During the simulations, a cubic box with ~76×76×76 Å was adopted, and Li atoms were only inserted into the central 20×20×20 Å region. The insertion process was set to about 25 Experimental studies show that the internal stress will accumulate inside Si particles with Li insertion, the magnitude of which depends on the lithiation mechanism. As shown above, combined with the evidences from earlier experiments, the initial lithiation of either c-Si or a-Si happens under a two-phase process condition. Thus, the a-LixSi/Si binary-phase is picked to study the stress distribution and the result is shown in Figure . Conf1 and conf3 of Li1308/c-Si21952 and conf2 of Li1308/a-Si21952 are selected to explore the stress distribution during lithiation. Starting from the structural cubic center, the range of 0<r20.0 Å is defined as the a-LixSi bulk region, 20.0<r40.0 Å is defined as the a-LixSi/c-Si or a-LixSi/a-Si interface region, and r>40.0 Å is defined as the c-Si or a-Si bulk region. indicate that amorphous Si anode may exhibit better resistance to fracture, and increasing the Li diffusivity, e.g. nanominiaturization, may be a good approach to improve the performance and stability of Si anode.