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

摘要

A process for etching silicon to form silicon pillars on the etched surfaces, includes treating silicon with an etching solution that includes 5 to 10M HF 0.01 to 0.1M Ag+ ions and 0.02 to 0.2M NO3− ions. Further, NO3− ions in the form of alkali metal, nitric acid or ammonium nitrate salt is added to maintain the concentration of nitrate ions within the above range. The etched silicon is separated from the solution. The process provides pillars, especially for use as the active anode material in lithium ion batteries. The process is advantageous because it uses an etching bath containing only a small number of ingredients whose concentration needs to be controlled and it can be less expensive to operate than previous processes.

主权项

1. A process of etching silicon to form silicon structures on the etched surfaces, the process comprising:
treating silicon with an initial etching solution comprising:
5 to 10M HF,0.01 to 0.1 M Ag+ ions,a concentration within a range of 0.02 to 0.2M NO3− ions, and subsequently adding further NO3− ions in the form of an alkali metal nitrate or ammonium nitrate salt, or in the form of nitric acid, to maintain the concentration of NO3− ions within the range specified for the initial etching solution; and separating the etched silicon from the solution.