Compact-Nanobox Engineering of Transition Metal Oxides with Enhanced Initial Coulombic Efficiency for Lithium-Ion Battery Anodes.
ACS Appl Mater Interfaces. 2018 Feb 22;:
Authors: Zhu Y, Hu A, Tang Q, Zhang S, Deng W, Li Y, Liu Z, Fan B, Xiao K, Liu J, Chen X
A novel strategy is proposed to construct a compact-nanobox (CNB) structure composed of irregular nanograins (average diameter ≈ 10 nm), aiming to confine electrode-electrolyte contact area and enhance initial Coulombic efficiency (ICE) of transition metal oxide (TMO) anodes. To demonstrate the validity of this attempt, CoO-CNB is taken as an example which is synthesized via a carbothermic reduction method. Benefiting from the compact configuration, electrolyte can only contact the outer surface of nanobox, keeping the inner CoO nanograins untouched. Therefore, the solid electrolyte interphase (SEI) formation is reduced. Furthermore, the internal cavity leaves enough room for volume variation upon lithiation and delithiation, resulting in superior mechanical stability of CNB structure and few generation of fresh SEI. Consequently, the SEI remains stable and spatially confined without degradation, and hence CoO-CNB electrode delivers an enhacned ICE of 82.2%, which is among the highest values reported for TMO-based anodes in lithium-ion batteries. In addition, the CoO-CNB electrode also demonstrates excellent cyclability with a reversible capacity of 811.6 mAh g-1 (90.4% capacity retention after 100 cycles). These findings open up a new way to design high-ICE electrodes, and boost the practical application of TMO anodes.
PMID: 29469567 [PubMed - as supplied by publisher]