In this study, MoS nanosheets are vertically grown on the inside and outside surfaces of the carbonized corn stalks (CCS) by a simple hydrothermal reaction. The vertically grown structure can not only improve the transmission rate of Li and electrons but also avoid the agglomeration of the nanosheets. Meanwhile, a new approach of biomass source application is presented. We use CCS instead of graphite powders, which can not only avoid the exploitation of graphite resources, but also be used as a matrix for MoS growth to prevent the electrode from being further decomposed during long cycles and at high current densities. Meanwhile, lithium-ion batteries show remarkable electrochemical performance. They demonstrate a high specific capacity of 1409.5 mA g at 100 mA g in the initial cycle. After 250 cycles, the discharge capacity is still as high as 1230.9 mAh g. Even at 4000 mA g, they show a high specific capacity of 777.7 mAh g. Furthermore, the MoS/CCS electrodes show long cycle life, and the specific capacity is still up to ∼500 mAh g at 5000 mA g after 1000 cycles.

A unique reversible conversion-type mechanism is reported in the amorphous molybdenum polysulfide (a-MoS) cathode material. The lithiation products of metallic Mo and LiS rather than Mo and LiS species have been detected. This process could yield a high discharge capacity of 746 mAh g. Characterizations of the recovered molybdenum polysulfide after the delithiaiton process manifests the high reversibility of the unique conversion reaction, in contrast with the general irreversibility of the conventional conversion-type mechanism. As a result, the a-MoS electrodes deliver high cycling stability with an energy-density retention of 1166 Wh kg after 100 cycles. These results provide a novel model for the design of high-capacity and long-life electrode materials.

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