Electrochemical amorphization as a method to increase the rate capability of crystalline silicon anodes for lithium-ion batteries

Anodes made of macroporous silicon were studied. The galvanostatic cyclic tests carried out in half-cells with a Li counter electrode in the mode, when charging capacity was limited by $Q_1$ = 1000 mAh/g, showed that the inclusion into the test program of a modifying cycle with an increased time of electrochemical lithiation allows to increase the charge/discharge rate upon the returning back to the initial mode. To interpret the obtained results, a two-phase model with a sharp $a$-Li$_{x}$Si/$c$-Si boundary was used. The introduction of a larger amount of lithium during the modifying cycle leads to an increase in the thickness of the amorphous layer, within which the introduction and extraction of lithium in subsequent cycles occur at a higher rate.