Confinement of ZIF-67-derived N, Co-doped C@Si on a 2D MXene for enhanced lithium storage.

ABSTRACT

A heterostructure composed of ZIF-67-derived nitrogen and cobalt-doped carbon enfolded silicon (C@Si) nanoparticles anchored on 2D MXene layers was constructed for boosting the performance of lithium-ion batteries (LIBs). The heterostructure anode demonstrated a high initial discharge capacity of 3021 mA h g-1 at 0.2 A g-1, retaining outstanding cycling stability with a reversible capacity of 520 mA h g-1 at 2000 mA g-1, and the coulombic efficiency remained above 97% after 500 cycles. The introduced Ti3C2 nanosheets and the cobalt-doped carbon can not only contribute to the interfacial transfer of Li+ and electrons but also buffer the volume expansion of Si.