Plant-cell oriented few-layer MoS2/C as high performance anodes for lithium-ion batteries

Abstract

MoS 2 with layered structure and high theoretical capacity (670 mAh· g − 1 ) has attracted great attention as a potential anode material for lithium-ion batteries (LIBs). However, the intrinsic low electronic conductivity and structural collapse during the lithiation/delithiation process hinder its practical application. In this study, a few-layer MoS 2 decorated biocarbon (MoS 2 /C) was exquisitely constructed employing petal cells as structure-directing agents. In the synthesis process, nucleation and growth of MoS 2 were restricted in the confined space of petal cells, and thus MoS 2 nanosheets (about 3–8 layers) grew vertically and dispersed uniformly on the petal-cell derived biocarbon matrix. The special structure effectively alleviates volume expansion and restack of MoS 2 during the lithiation/delithiation process, while the in situ generated biocarbon improves the conductivity of electrode, thus boosting electron transportation and Li + diffusivity. Moreover, theoretical calculations reveal the lower Li + migration barrier energies and improved Li + diffusion kinetics in MoS 2 /C hetero-layer. Consequently, the MoS 2 /C exhibits remarkable rate performance and cycle stability, showing a superior reversible capacity (951 mAh· g − 1 over 500 cycles at 100 mA· g − 1 ) much larger than bulk MoS 2 (108 mAh· g − 1 ) and biocarbon (355 mAh· g − 1 ). This study provides a convenient and effective strategy to design advanced electrodes for the next-generation energy storage and conversion systems.