Zinc Oxide Quantum Dots Embedded Porous Carbon Nanosheets for High-Capacity and Ultrastable Lithium-Ion Battery Anodes

Abstract

Carbon materials are widely used in lithium-ion batteries (LIBs) due to their high performance, safety, and reliability, along with low cost and easy availability. However, the low lithium storage capability of bare carbon materials limits the further improvement of the capacity of LIBs. Here, we report a facile self-poring strategy for the synthesis of trace amounts of ZnO quantum dots (QDs) (∼5 nm) embedded in highly porous carbon nanosheets by using the metal centers of a Zn-based metal-organic ligand structure as a pore-creating agent. Benefiting from the synergistic functions of nanostructuring, heterocomponent doping, and QDs effects, the as-prepared materials deliver superior lithium storage properties in comparison with the existing carbon-based materials—2,300 mAh g−1 at 0.2 A g−1, ∼600 mAh g−1 at 10 A g−1, and ∼700 mAh g−1 after 3,000 cycles at 5 A g−1—and are promising candidates for next-generation high-capacity LIB electrodes.