A method of fabricating structured particles composed of silicon or a silicon-based material and their use in lithium rechargeable batteries.

摘要

A method for treating silicon to form pillars (see Figure 2), for use as the active anode material in Li-ion batteries is described. The solution used in the process comprises: 0.01 to 5M hydrogen fluoride (HF), 0.002 to 0.2M of metal ions capable of nucleating on and forming a porous layer comprising regions of elemental metal on the silicon surface, such as silver (Ag); 0.001 to 0.7M of an oxidant selected from the group oxygen (02), ozone (03), hydrogen peroxide (H202) the acid, ammonium or alkali metal salt of nitrate (NO3-), peroxodisulfate (S2O82-), nitrite (NO2-), borate (B4072-) and perchlorate (C104-) or a mixture thereof. The process may proceed via two steps; a nucleation phase followed by an etching phase where a different solution composition of HF can be used. Further additions of nitrate and HF can also be made during the course of the process. The silicon used in the process may comprise powdered silicon or granulated silicon.