摘要
Although Si-based nanomaterials provide incomparable lithium ion storage ability in theory, it suffers from low initial Coulombic efficiency, electrical disconnection, and fracture due to huge volume changes after extended cycles. As a result, it leads to a severe capacity fading and an increase in internal impedance. Herein, Ti-elemental MXene was employed as a matrix for the intermediate product of Si electrodes. The boundary between the inner core of pristine Si and its outer shell of amorphous Li x Si alloy was reconstructed. Smaller amorphous aggregates were observed in the MXene&Si hybrid electrode after 500 cycles by using transmission electron microscopy. Consequently, an enhanced specific capacity was achieved as MXene as a matrix enables loading amorphous Si.
Although Si-based nanomaterials provide incomparable lithium ion storage ability in theory, it suffers from low initial Coulombic efficiency, electrical disconnection, and fracture due to huge volume changes after extended cycles. As a result, it leads to a severe capacity fading and an increase in internal impedance. Herein, Ti-elemental MXene was employed as a matrix for the intermediate product of Si electrodes. The boundary between the inner core of pristine Si and its outer shell of amorphous Li x Si alloy was reconstructed. Smaller amorphous aggregates were observed in the MXene&Si hybrid electrode after 500 cycles by using transmission electron microscopy. Consequently, an enhanced specific capacity was achieved as MXene as a matrix enables loading amorphous Si.
基金
financial support provided by the Joint Foundation of Liaoning Province National Science Foundation
Shenyang National Laboratory for Materials Science (Grant No. 20180510047)
the National Natural Science Foundation of China (Grant Nos. 91545119 , 21761132025 , 21773269 and 51872115)
the Youth Innovation Promotion Association CAS (Grant No. 2015152)
the Program for JLU Science and Technology Innovative Research Team (JLUSTIRT, 2017TD-09)
“Double-First Class” Discipline for Materials Science & Engineering
Natural Science Foundation of Anhui Province (1608085ME93)
the Fundamental Research Funds for the Central Universities (JZ2018YYPY0305)
the 111 Project “New Materials and Technology for Clean Energy” (B18018)
