CNT network crosslinked by metal Co2+ for stabilizing SnO2 anodes

Abstract

Porous carbon materials are considered potential replacements for metal carriers in Li–SnO2 batteries. Here, a 3D hierarchical porous carbon nanotube (CNT) scaffold was used as a collector to host SnO2. The novel collector comprised Co2+-doped porous carbon (PC) slices and a CNT network. The new Co–PC/CNT electrode demonstrated a high loading capacity of SnO2, accommodated the volume expansion of SnO2, and prevented its aggregation. Co played an important role in improving the initial discharge capacity and coulombic efficiency of the electrode. The SnO2–Co–PC/CNT electrodes exhibited outstanding electrochemical performance. The first-discharge specific capacity reached 2067 mAh·g−1, and the utilization rate of active materials reached 82.92% at a current density of 100 mAh·g−1. After 100 cycles, the specific discharge capacity remained greater than 698 mAh·g−1, with a coulombic efficiency of 99.53%.