Artificial Solid Electrolyte Interphase To Address the Electrochemical Degradation of Silicon Electrodes

作者：Li Juchuan^*; Dudney Nancy J; Nanda Jagjit; Liang Chengdu

来源：ACS Applied Materials & Interfaces, 2014, 6(13): 10083-10088.

DOI：10.1021/am5009419

• silicon anodes
• artificial solid electrolyte interphase
• electrochemical degradation
• solid electrolyte
• lithium-ion batteries

Electrochemical degradation on silicon (Si) anodes prevents them from being successfully used in lithium (Li)-ion battery full cells. Unlike the case of graphite anodes, the natural solid electrolyte interphase (SE!) films generated from carbonate electrolytes do not self-passivate on Si, causing continuous electrolyte decomposition and loss of Li ions. In this work, we aim at solving the issue of electrochemical degradation by fabricating artificial SEI films using a solid electrolyte material, lithium phosphorus oxynitride (Lipon), which conducts Li ions and blocks electrons. For Si anodes coated with Lipon of 50 nm or thicker, a significant effect is observed in suppressing electrolyte decomposition, while Lipon of thinner than 40 nm has a limited effect. Ionic and electronic conductivity measurements reveal that the artificial SEI is effective when it is a pure ionic conductor, but electrolyte decomposition is only partially suppressed when the artificial SEI is a mixed electronic-ionic conductor. The critical thickness for this transition in conducting behavior is found to be 40-50 nm. This work provides guidance for designing artificial SEI films for high-capacity Li-ion battery electrodes using solid electrolyte materials.

• 出版日期2014-7-9