Boosting properties of 3D binder-free manganese oxide anodes by preformation of a solid electrolyte interphase

Abstract

Huge irreversible capacity loss prevents the successful use of metal oxide anodes in Li-ion full cells. Here, we focus on the critical prelithiation step and demonstrate the challenge of electrolyte decomposition on a pristine anode in a full cell. Both an electrochemical activation process (54 h) with Li metal and a new electrolytic process (75 min) without Li metal were used to preform complete solid electrolyte interphase (SEI) layers on 3 D binder-free MnOy-based anodes. The preformed SEI layers mitigated the electrolyte decomposition effectively and widened the working voltage for the MnOy/LiMn2O4 full cell, which resulted in a big boost of the specific energy to 300 and 200 W h kgcathode−1, largely improved cycling stability, and much higher specific power (4200 W h kgtotal−1) compared to conventional Li-ion batteries. Detailed characterization, such as cyclic voltammetry, scanning transmission electron microscopy, and FTIR spectroscopy, gives mechanistic insight into SEI preformation. This work provides guidance for the design of anode SEI layers and enables the application of oxides for Li-ion battery full cells.