Impact of exposing lithium metal to monocrystalline vertical silicon nanowires for lithium-ion microbatteries

• Main Authors: Refino, Andam Deatama, Adhitama, Egy, Bela, Marlena M., Sadhujan, Sumesh, Harilal, Sherina, Eldona, Calvin, Bremers, Heiko, Bashouti, Muhammad Y., Sumboja, Afriyanti, Stan, Marian C., Winter, Martin, Placke, Tobias, Peiner, Erwin, Wasisto, Hutomo Suryo
• Other Authors: School of Materials Science and Engineering
• Format: Article
• Language: English
• Published: 2024
• Subjects: Engineering; Monocrystalline Silicon; Thermal Evaporation
• Online Access: https://hdl.handle.net/10356/173528
• Institution: Nanyang Technological University

Silicon has attracted considerable attention for use as high-capacity anodes of lithium-ion microbatteries. However, its extreme volume change upon (de-)lithiation still poses a challenge for adoption as it leads to severe active lithium loss that shortens the cycle life. Here, we fabricate three-dimensional monocrystalline vertical silicon nanowires on a silicon wafer using low-cost metal-assisted chemical etching, then cover them with lithium using thermal evaporation prior to the battery operation as the pre-lithiation step, to investigate its impact on electrochemical performance. To reveal the underlying physical and electrochemical mechanisms, we also process a comparative planar monocrystalline silicon. We find that pre-lithiation results in improved (de-)lithiation behavior, especially in planar silicon-based cells, while silicon nanowire-based cells exhibit low capacity in early cycles. This study sheds light on the surface design and structural modification of monocrystalline silicon nanowires with respect to pre-lithiation by lithium thermal evaporation.