Double-Layer Carbon Coated Mno Nanocapsules with Multilayer Structure for Lithium-Ion Storage

Abstract

The multi-layer buffer structure with double-layer carbon sandwiched MnO nanoparticles (HNC@MnO@NC) is designed by hard template and hydrothermal methods combined with the pyrolysis of polydopamine. The internal nitrogen-doped hollow carbon layer (HNC) can not only increase the electron migration rate, but also prevent the MnO nanoparticles in the middle from gathering together which provides more active sites for lithium ions in the composite material. The external nitrogen-doped carbon layer (NC) and the presence of oxygen vacancies of MnO can further accelerate the electron transfer of the composite and promote the lithium storage performance of the anode materials based on HNC@MnO@NC. The well-designed nanocapsule structure of HNC@MnO@NC with stable double-layer carbon shows the enhanced cycling stability and superior electrochemical performance to HNC and HNC@MnO, discharge specific capacity of 820 mAh/g for 1000 cycles at 1 A/g.

Keywords: MnO, hierarchical structures, lithium-ion battery, cycling stability