Laser-patterned Si/TiN/Ge anode for stable Si based Li-ion microbatteries

Abstract

Progress in micro/nano-electro-mechanical system (M/NEMS) and microelectronics technologies urgently require the synchronous development of the micro/nano energy storage systems. Herein, a novel patterned Si/TiN/Ge electrode is fabricated on the Si substrate surface by the facile femtosecond-laser direct writing and the microelectronic thin film deposition techniques. The surface-engraved Si/TiN/Ge electrode displays superior cyclability and rate capability when evaluated as anode for lithium ion microbatteries (LIMBs). The patterned TiN interlayer can act as an effective buffer layer to optimize the Li ions storage in the Si substrate, and the introduction of the Ge nanocomposites would further enhance the areal capacity, thus eventually bring the improved electrochemical performance. Moreover, the Li ions storage behaviours are experimentally investigated from the post morphologies of all the cycled electrodes, and theoretically studied by the COMSOL Multiphysics simulations and the first principles calculations. These results would shed light on the new strategy to design and exploit other high-performance Si based LIMBs.